The data recorded during the site survey in the Zhangzhou area in Fujian between October 23,2007 and December 3,2007 was analyzed. The main methods adopted for the noise level of this area are noise root mean square(RMS),noise power spectrum density and noise coherency function. The research result indicates that noise level of the survey sites are higher in 1-10s period,which is the main frequency band of preliminary microseism,and also,two main noise sources were found in 1.5Hz and around 5Hz. According to the arithmetic,the direction and frequency band of the noise source were analyzed and academic proofs were presented. At last,we obtained that the noise source in 1.5Hz was made by the water wave aroused by the wind in the reservoir region and the noise source around 5Hz was made the electric field in north-east direction.