Three maize varieties were used in this study. Starch granule size distribution in horny and silty en-dosperm was determined by laser diffraction particle size analyzer. The results indicated that horny endosperm andsilty endosperm showed three peak curve in starch granule volume distribution, and single peak curve in starch gran-ule number distribution. Starch granule surface area showed three peak curve in horny endosperm, but four peakcurve in silty endosperm. According to the concave point of double peak curve, taking 3.519μm and 7.422μm aslimit, starch granules were divided into three types: small（＜3.519μm）, middle（3.519~7.422μm） and large（＞7.422μm）. In horny endosperm, the volume and surface area ratio of middle starch granule（4.46% ~6.14%,6.71%~8.14%） and the number ratio of middle and large starch granule（0.47%~0.56%, 0.32%~0.38%） were higher than those of silty endosperm（1.36%~5.68%, 1.81%~6.63%, 0.10%~0.31%, 0.28%~0.31%）. However,in silty endosperm, the surface area and number ratio of small starch granule（54.73%~57.31%, 99.39%~99.59%）were higher than those of horny endosperm（51.95%~53.36%, 99.06%~99.21%）. In the process of actual processing and utilization of maize, different types of endosperm should be selected to meet our needs to realize the rational and efficient utilization of maize endosperm.