Abstract: Using wheat variety Huacheng 3366 as the test material and set four phosphorus levels which the P₂O₅ consistency of 0，60，120，and 180 kg/hm²，respectively，the effect of phosphate fertilizer dosage on the starch granules size distribution and starch viscosity parameters of wheat endosperm was studied. The test results showed that when the phosphate fertilizer dosage was 0 ~ 120 kg/hm²，as the amount of phosphate fertilizer significantly increased，the volume and surface area percentage of B- type starch granules increased and the volume and surface area percentage of A- type starch granules reduced. When the phosphate fertilizer dosage was 120 ~ 180 kg/hm²，increasing phosphate fertilizer had no significant effect on the volume and surface area percentage of A- type and B- type starch granules. Increasing the application of phosphorus fertilizer in the range of 0 ~ 120 kg/hm² significantly increased the trough viscosity，peak viscosity，and final viscosity of wheat grain starch，but had no significant effect on the breakdown and setback value. When the phosphate fertilizer dosage exceeded 120 kg/hm²，the amount of phosphate fertilizer had no significant effect on the above starch viscosity parameters. The above analysis demonstrates that increasing the amount of phosphate fertilizer changed the starch particle size distribution when the phosphate fertilizer dosage is 0 ~ 120 kg/hm². That is to increase the volume and surface area percentage of B- type starch granules，reduce the volume and surface area percentage of A- type starch granules，and then increase the starch viscosity parameters such as peak viscosity.

Key words: wheat, phosphate fertilizer, starch, granule size distribution, viscosity parameters