Abstract: field measurements of acid precipitation at Fenghuan Mountain and the calculation of air trajectory were conducted in the summer of 1993 and 1994.The volume weighted average pH value of serious acid rain in 1993 is 4 71 and that in 1994 is 4 54.The calculation,in the first time,shows that the acid rain in this area is evidently suffered the effects from Korea Peninsula and southern Japan. Because the rainfalls are concentrated in summer in this area and the prevailing wind direction at the same time is southeast.So the transportation effects from outside is an important factor for the formation of acid ran in this area.