Objective To investigate the impact of organophorous pesticide exposure on semen quality and other risk factors of semen qualityMethod Questionnaire investigation, external genital examination and laboratory examination of semen quality were conducted on 322 subjects, who were divided into exposed and control group, each consisting of 161 subjects. Results Multivariate analysis showed that educational level and years of alcohol drinking had effect on semen volume. Compared with subjects with primary school education or lower, those with junior high school education had higher value of semen volume(OR=1.961). Proportion of subjects with high semen volume decreased with the increasing years of alcohol drinking (OR=0.962). Organophosphorous pesticide exposure could result in the decline of the number of sperms with progressive forward progression (OR=0.528), figure of semen density (OR=0.266), semen viability (OR=0.398) and percentage of normal sperm morphology (OR=0.281). There are possible relationships between the season of semen collection and the number of sperms with progressive forward progression, semen viability and percentage of normal sperm morphology. Compared to summer, values of the above three indices would be higher in winter (OR was 2.272, 4.060 and 5.249, respectively).Conclusion Exposure to organophosphorous pesticide could result in the deterioration of semen quality of the peasants.