Abstract: In the produce process of save sulphuric acid phosphate fertilizer, three new modified phosphate fertilizers by mixing with certain proportion additive were developed. Chemical analysis indicates that the proportion of soluble phosphorus in modified phosphate fertilizer reduced. The result of pot cultivation showed that three modified phosphate fertilizers were better than superphosphate under the equal weight condition. Though the analysis of crystal structure of modified phosphate fertilizers by XRD and IR, the great change of crystal structure was found. Change of crystal structure reduced the available phosphorus in modified phosphate fertilizers fixed in soil, and the bioavailability increased greatly. That is the main reason to the increase production of biomass.