Abstract: In order to find economical and reasonable treatment process for polluted reservoir water, the reservoir source water in Shenzhen City was treated in pilot-scale study to research the effect on removal rate of organics, ammonia nitrogen, algae, odour, turbidity and Ames assays, when biological pretreatment, activated carbon filter and ozone-biological activated carbon filter was added to the conventional water purification process. The results showed that: the biological pretreatment could effectively decrease the concentration of organics, ammonia nitrogen and algae, make up for the conventional purification process, and management was simple, infrastructure costs and running costs gained less, when activated carbon filter or ozone-biological activated carbon filter was added, organic concentration and odour was reduce further, the water quality improved overall, but infrastructure costs and running cost soared.