Primary production,chlorophyll-a and alkaline phosphatase activity of periphyton can indicate its water purifying capacity.Five artificial substrates with different surface configurations and physicochemical characteristics were selected during this experiment.They were glass slide,PVC film,soft substrate,combined substrate and elastic substrate.The primary production, chlorophyll-a and alkaline phosphatase activity of periphyton attached on these five different substrates were investigated in situ.The results showed that physicochemical characteristics of artificial substrates were proved to be the key factors affecting the stability of periphyton community,primary production,chlorophyll-a and alkaline phosphatase activity.Generally during in situ attachment process,the maximum mass of periphyton appeared on the 8th to 10th day while periphyton primary production,chlorophyll-a and metabolic activity were also showed the highest.Primary production,chlorophyll-a and alkaline phosphatase activity of the periphyton attached on elastic and soft substrates were significantly higher than those on other three substrates.The net primary production of the periphyton attached on the elastic substrate was 164.21 mgO₂/(g·h),the highest of those on the five artificial substrates.Compared with the soft substrate,the elastic substrate was more economic and better optimal artificial substrate for water quality restoration.