Battle of Busan ( 1592 ) The Battle of Busan of 1592 ( or more accurately , the Battle of Busanpo or Battle of Busan Bay ) ( 釜山浦 海戰 ) was a naval engagement that took place on 1 September 1592 during the first phase of the Japanese invasions of Korea . It was a Korean surprise attack on the fleet of Toyotomi Hideyoshi stationed at Busan , and its main objective was to regain Busan to Joseon , which led thorough cutoff of the supply line of the army of Japanese forces . In this battle , officer Woon ( ) and six soldiers died , and the Japanese lost over 100 ships , but the control of Busan was maintained under the Japanese forces as well as the control of the sea from Japan to Busan . The occupation of Busan by the Japanese forces had been kept until November 1597 , when the retreat of the Japanese forces was finished due to the death of Hideyoshi . Background . After commander Yi Sun Shin ' s fleet decisively defeated Japanese in the Battle of Hansando on July 8 , the Japanese had to change their war strategy . Their strategy was to deliver more land forces and supplies by sea to the northern part of the Korean peninsula and then they would march into Ming China . With the failure of this strategy , Japanese troops in the northern provinces of Joseon Korea had to suffer from starvation and shortages of supplies . To invade China , they needed to secure war supply routes . The alternate plan was to advance troops and supplies by roads , but this route was blocked by the " Uibyeong " ( " Righteous Army " ) . Many Korean civilians and Buddhist monks formed a voluntary army and attacked Japanese troops . Formation of united Joseon fleet . After the Battle of Hansan Island , in which commander Yi Sun - sin ' s navy won against the Japanese navy around mid - July , they remained silent for nearly a month . In mid - August Japanese Kato Yoshiaki ' s army , Kimura ' s army , and Okamoto ' s army retreated from Hanyang , the later capital of Joseon dynasty , to Gyeongsang Province . Around this time , most of the Japanese troops retreated to Gimhae to secure their munitions . During that time in Busan , there were 8 , 000 soldiers and 430 vessels protecting the coast . Commander Yi , however , sent spy ships to Busan port and found out there were about 470 warships there . Commander Yi believed that the Japanese were retreating to their country , so Gyeongsang Province Governor ( 慶尙右水營 ) Kim Soo requested that Commander Yi block their sea route . Therefore , Commander Yi with Commanders Won Gyun and Yi Eok Ki united their fleets , for a total of 166 vessels . On their way to Busan , Commander Yi defeated 24 Japanese ships at Seopyeongpo ( 西平浦 ) , at the Battle of Dadaejin ( 多大浦 ) , and at Jeolyoungdo ( 絶影島 ) . The combined Joseon fleet defeated the Japanese navy repeatedly , largely as a result of their well - trained sailors and the Joseon ships ' medium and long range cannons . Battle of Busanpo . Off the coast of Busan , the united Joseon fleet realized that the Japanese navy had readied their ships for battle and the Japanese army had stationed themselves around the shoreline . The united Joseon fleet assembled in the " Jangsajin " ( 長蛇陣 ) , or " Long Snake " formation , with many ships advancing in a line , and attacked straight into the Japanese fleet . Overwhelmed by the Joseon fleet , the Japanese navy abandoned their ships and fled to the coast where their army was stationed . The Japanese army and navy joined their forces and attacked the Joseon fleet from the nearby hills in desperation . The Joseon fleet shot arrows from their ships to defend and restrict their attacks , and in the meantime concentrated their cannon fire on destroying Japanese vessels . Comparisons . In terms of size , the Joseon ships were one - third that of Japanese ships . Although commander Yi destroyed over 100 ships , he did not order his soldiers to pursue the Japanese on shore , probably because he recognized that close hand - to - hand combat skills of the Joseon were significantly weaker than those of the samurai . In addition , the Joseon soldiers were exhausted from long sea travel and battle , and would have been heavily outnumbered on land . Up to that point , Commander Yi had not fought with numbers of soldiers , but rather with ships and cannons . Yi reinforced disadvantages in number of soldiers with heavy use of firearms . The Japanese also had a well - trained cavalry , which was another aspect the Joseon army lacked . Instead of the Joseon fleet . Yi lost one of his cherished officers , by the name of Woon . Impact . After this battle , the Josen naval activity substantially subsided . Before then , there were 9 naval battles during 3 month since May , 1592 , which were led by Yi , but the next naval battle was took place 6 months later in February , 1593 . The Japanese forces succeeded to protect their position in Busan bay as well as the supply line from Japan . Since the Japanese forces realized the importance of defense lines of Busan bay to secure the supply line , they tried to bring the west area of Busan under their control , where the Josen navy came . This attempt led the Battle of Jinju in October 1592 , in which General Kim Si - min triumphed over 20 , 000 Japanese forces , and Battle of Jinju in June 1593 , in which Japanese forces finally captured the castle in Jinju . Argument in Japan . It is told in Korea that the Joseon navy won this battle and the Japanese military lost control of the seas around the Josen . On the other hand , in Japan , with referencing the official history of the Joseon and referencing the military mails between Japanese Daimyou , it is told that the result was strategic victory of Japan , that is , the Japanese forces succeeded to protect control of the Busan bay , which also led to protected supply line between the Bay and Japan . For example , Annals of the Joseon Dynasty , which is one the official history record summarized this battle as strategic failure as follows , " 李舜臣等攻釜山賊屯 , 不克 。 倭兵屢敗於水戰 , 聚據釜山 、 東萊 , 列艦守港 。 舜臣與元均悉舟師進攻 , 賊斂兵不戰 , 登高放丸 , 水兵不能下陸 , 乃燒空船四百餘艘而退 。 鹿島萬戶鄭運居前力戰 , 中丸死 , 舜臣痛惜之 。 " . This can be translated as follows , " Yi Sun Shin and his fleet attacked Busan where the enemy forces stationed , but failed to defeat them . Since Japanese soldiers were often defeated in sea fights , they gathered in the fortress in Busan and Dongnae , which guarded the naval ships . Yi Sun Shin and Won Gyun attacked the Busan bay on vast numbers of ships , but the Japanese soldiers did not fight , and climbed to higher position and shot an arquebus . Thus Josen marines were unable to land then after burning 400 empty ships , Yi ' s fleet retreated . 鹿島萬戶 Chong Woon ( ) was shot and died during the hard fighting , and Yi Sun deeply regret the lost . "