Gongsun Yuan
In 232, Lu Mao was summoned to the Wu imperial court and was appointed as a Consultant () and Master of Writing in the Selection Bureau. The Wu emperor Sun Quan hated the warlord Gongsun Yuan for breaking his promise to ally with him against Wu's rival state, Cao Wei. He planned to personally lead an army to attack Gongsun Yuan. Lu Mao wrote a memorial to Sun Quan to dissuade him from launching the campaign, in which he explained the perils of travelling far to attack a distant enemy and pointed out some negative consequences that may result from the campaign, such as the Shanyue tribes taking advantage of Sun Quan's absence to cause trouble in the Wu region. Sun Quan disagreed with Lu Mao. Lu Mao then wrote another memorial to Sun Quan, advising him to refrain from attacking Gongsun Yuan, and focus on maintaining stability in Wu and making long term defence preparations instead. Sun Quan felt that Lu Mao was very sincere when he wrote the memorial so he abandoned the idea of attacking Gongsun Yuan.