In order to investigate the effect of extrusion treatment on the characteristics of infant rice powder in the dry process， this study analyzed the differences of physicochemical properties and the digestion characteristics of rice powder with four typical varieties of rice（Northeast rice， Indica rice， Thai rice， and Glutinous rice） by extrusion. The results showed that the starch composition among different rice varieties under some extruding conditions was significantly different （P<0.05）， as well the swelling degree， water absorption index and water solubility index. The content of resistant starch in indica rice was the highest， close to 15%， and the content of rapid digestion starch was less than 75% in glutinous rice. The pepsin digestibility and total protein digestibility of glutinous rice were lower than those of the other three kinds of rice powder， which may be due to the different structure and composition of protein in glutinous rice. The results of this study provide the theoretical basis for the application of extrusion technology in infant rice powder production and the effect on different rice varieties.