Abstract: The water retaining agent with interpenetrating networks of sodium acrylate(SA)-based superabsorbent and sodium PVA sulfate(SPS) were prepared by the static-state aqueous solution polymerization method. The un-pretreated industrial acrylic acid and PVA(molecular weight=124000) were used as reaction raw materials. The strong hydrophilic ionic function groups were introduced into PVA molecules through the Chlorosulfonic acid sulfonation method to prepare SPS. The formation of SA-IP-SPS interpenetrating networks resulted in the improved salt tolerance and mechanical properties of this water retaining agent. In addition the performance of SA-IP-SPS water retaining agents in improving water holding capacity and amending water-stable aggregates of Lateritic Red Soil (from South China) were investigated in detail. The results of the comparison experiment showed that the SA-IP-SPS water retaining agent was approximate to the AA-AM water retaining agent in applying performances, but they were remarkably superior to SA water retaining agents.