Maizuru Naval District
From November 1936, "Tatsuta" was paired with her sister ship "Tenryū" in the 10th Cruiser Squadron of the IJN 3rd Fleet, replacing the cruiser . As the situation between Japan and China deteriorated into the Second Sino-Japanese War, "Tatsuta" supported the landings of the Imperial Japanese Army and Japanese naval forces in Shanghai, and the blockade of the Chinese coast. As a component of the IJN 5th Fleet, on 10 May 1938 she covered the landing of Japanese forces at Amoy and on 1 July 1938 supported operations in Guangzhou. "Tatsuta" and "Tenryū " operated in Chinese waters until 14 December 1938, when they were withdrawn from front line service and assigned to the reserves. From 1 December 1939, "Tatsuta" was based at Maizuru Naval District.