Objective To study the optimum extration process of polysaccharides from Meretrix meretrix Linnaeus.A spectrophotometry method for content determination of polysaccharides from Meretrix meretrix Linnaeus was established with Phenol-sulfuric acid coloration.Methods The samples were extracted by ultrasonic wave,dissolved in 50mL,4mol?L~(-1) HCl and heated to hydrolyze by acid.The contents of polysaccharides from Meretrix meretrix Linnaeus were determined by spectrophotometry at 490nm.Results Extracted for thirty minutes by ultrasonic wave,two times,and acidic hydrolysis were the optimum technology.The calibration curve was linear over the range of 4.848～24.242mg?L~(-1).The regression equation was C=28.69A+0.229(r=0.9992).The average recovery rate was 100.67% and RSD was 2.83%(n=6).Conclusion The method was proved to be simple,accurate and reliable,and could be used to extract and determine the polysaccharides from Meretrix meretrix Linnaeus.