By the laboratory experiments,the effects of konjac super absorbent polymer (KSAP) on water preservation in soil were studied using factorial designed experiment. Results showed that the effects of soil water preservation were significant(P<0.01) when different additions,different dosages and particle diamenters ters of KSAP were added to the soil,whereas the frequency of irrigation on water preservation of KASP was not significant. The effectivewater in sand,red soil,and brown soi1 were increased by 32.7%,18.1%and 24.3%,respectively,when KSAP(0.30%,particle diameter 0.80mm) was sprayed to surface.