This study compared physicochemical properties of Yunnan soft rice starch with indica rice, japonica rice and glutinous rice starches. The results showed that the four rice starches content were between97.90% and 99.29%.The soft rice of the content of amylose higher than glutinous rice, which belong to low amylose content rice.The four rice starches performed low clarity;compared with the other three rice starches, soft rice starch performed a lower solubility and highest swelling power.The anti-precipitability of soft rice starch behind the glutinous rice starch; the hardness, gumminess and chewiness of soft rice were between japonica rice and glutinous rice, however, springiness and cohesiveness were less than japonica starch; With the increase of shear rate, the apparent viscosity of soft rice starch fall at the fastest rate; the pasting temperature of soft rice starch was in the range of 59.9℃ to 73.9℃, and the retrogradation and cold stability of soft rice starch are slightly worse than that of glutinous rice starch. The enthalpy of soft rice was the lowest in four rice starches. The morphology of soft rice starch are irregular polygonal, and part of the starch surface was hollow, 92.60% of soft rice starch size ranged from 0 to 20μm.