Total　count　of　bacteria　and　total　coliforms　group　were　applied　as　the　monitoring　index,　and　the　secondary　effluent　from　urban　wastewater　treatment　plant　were　employed　as　water　samples　in　this　study.　The　disinfection　efficacy　by　chlorine　or　chloramines　individually　or　combination　of　potassium　permanganate　and　chlorine　were　investigated　in　wastewater　treatment　process,　and　the　control　effect　of　trihalomethane　formation　was　surveyed　also.　The　feasibility　of　practical　application　on　synergistic　disinfection　of　potassium　permanganate　and　chlorine　was　investigated　on　both　aspects　of　chemical　safety　and　microbial　safety.　The　results　show　that　chlorine　disinfection　have　no　advantage　compared　with　chloramine　disinfection　for　seriously　polluted　wastewater,　especially　with　higher　concentration　of　organic　nitrogen　and　ammonia　nitrogen.　The　disinfection　efficacy　of　synergistic　disinfection　of　potassium　permanganate　and　chlorine　is　improved　distinctly　than　that　of　chlorine　disinfection　individually,　and　trihalomethane　formation　is　clearly　less　too.　Therefore,　both　aspects　of　chemical　safety　and　microbial　safety　of　treated　water　can　be　improved　by　synergistic　disinfection　of　potassium　permanganate　and　chlorine　process.