The superabsorbent composite resin is synthesized from diatomite and polyacrylamide by liquid method.The primary influential factors of capacity of absorbing water are experimentally investigated.The results show that the capacity of absorption reaches a plateau value of 611 g/g when dosages of diatomite,starch,NaOH,initiator,crosslinker respectively are 30%,30%,60%,1.5%,0.03% of monomer.The performances of superabsorbent composite resin are improved by adding diatomite.