Abstract: To explore the slow-release and water-saving effect of mixture of super absorbent polymers and fertilizer, In this paper, nitrogen, phosphorus and potassium, three nutrients necessary for plants, were mixed with superabsorbent polymer to produce a compound named compound-SAP that was able to retain these nutrients and water in an enduring way. The efficacy of the compound-SAP was tested by using plot method and applying it to plants divided into different treatments and comparing its effects on them by observing Plant growth indicators and N, P and K content of plant and plant water content. The results showed: there was not a significant difference between the emergence rates of the reference sample and treated with the compound concerned, mixed fertilizers or superabsorbent polymers of different particle sizes. The seedling growth of treated with the compound-SAP was 12-47 percent higher than that of the reference, and the biomass of the group treated with the compound was 1.3-5.6 times higher than that of the reference; the treated with compound SAP was able to significant increase water content and flow of water of plant; the biomass of the group with the same level of fertilizer treatment was 3.88 times higher than the average. The nitrogen apparent utilization rate of the group treated with the compound was 0.2-1.9 times larger than that of the group treated with fertilizers of the same nutrient level, the phosphorus apparent utilization rate of was 0.23-2 times larger, but the rate of potassium was 33 percent-200 percent smaller. The Conclusions show that: the compound-SAP has no significant effect on the emergence rate and is able to significantly increase seedling growth of annual ryegrass. The compound-SAP significantly increased the apparent utilization of nitrogen and potassium, the compound of nutrients and superabsorbent polymer increases the utilization of fertilizer, thus making it possible to use less fertilizer to achieve the same growth effect. Therefore, a compound that mixes nutrients and superabsorbent polymer by made mixture method is able to retain water and fertilizer.