Water absorbability of six super absorbent polymers was compared in NaC1, KC1, CaCl2 solution with concentration ascending from 0 to 0.5 mol/L The result concluded that following with the electrolyte concentration ascending, water absorbability had a decreasing trend. Water absorbability was measured and compared when the distilled water pH value changed from 2 to 12. It can be concluded that, when pH value between6 roB, super absorb ent-polymers can keep a more steady and better performance of absorbing water than pH value beyond the range of 4 to 10. Super absorbent-polymers can affect the soil water evaporation rate, the more super-absorbent-polymers are used, the lower evaporation rate is. In all these experiment, GN had a best performance among the group. Soil characters can affect super- absorbent polymers’ role of decreasing soil water evaporation rale in the experiment with GN. In loam soil, the role was more obviously.