This study aims to analyze the characteristics of the dispatching process and information about the Later Jin through the 『Diplomatic Report on Shenyang』 of Lee Jun, who was dispatched as an envoy to the Later Jin in 1635. Diplomatic reports on Shenyang from different periods were reviewed together to analyze the selection of diplomats, their travel to Shenyang, and the information they collected. First, the envoys sent to Later Jin were mostly military officers or officials with a history of service in the North (Pyeongan, Hamgyong, and Hwanghwang provinces). Lee Jun, a military officer, had never been sent to Shenyang as a envoy, but was selected as an envoy because he had served as a district magistrate in the North several times. Second, before the 1630s, Xinxing(新城/東京), near Yuyuan, served as an intermediate base for diplomatic travel, but after the 1630s, escorts began at Tongyuanbo, located further south than Xinxing. This shows that the Later Jin's jurisdiction gradually expanded southward. Third, the Later Jin controlled Joseon envoys as they traveled to Shenyang and while they were in Shenyang. This was to prevent Joseon envoys from contacting Jurchen people and captives to learn about Later Jin situation. However, Lee Jun's case was less restrictive than previous Joseon envoys. Fourth, Lee's main concern was the state of the Later Jin-Ming war. After gathering information, he determined that in 1634, the Later Jin attacked China but suffered significant losses. Fifth, Lee used the opportunity to ascend to Shenyang's castle to confirm Later Jin's national power. Shenyang's castle had more than 10,000 households, but the population was small compared to the number of households. He also learned more about the types and quantities of gunpowder weapons for defense. The above studies illustrate the circumstances and perceptions of a period of relatively reduced Joseon-Later Jin conflict prior to the Byeongja Horan(1637).