Objective To undenstand the effects of performing the project of water and environmental sanitation (WES) on the environmental sanitation in countryside. Methods In the WES project-performed counties, the densities of fly and maggot, and the odor complains in household latrines were investigated, the status of peasants' hygienic knowledge and personal sanitary behavior and habits, and satisfaction at the sanitary latrines were investigated by means of a unified questionaire in 8 latrine-improved villages and one latrine-unimproved village (control village). Results The densities of fly and maggot and the oder complains in household improved latrines were all significantly lower than those in control household latrines. In the WES project-performed villages, higher levels of hygienic knowledge, better sanitary behavior and habit were observed in peasants compared with those in control village. 94.0% of the peasants in latrine-improved households satisfied the sanitary latrines. Conclusion Performance of WES project rose the whole level of the environmental sanitation in rural area.