【Objective】 To analyze the formation mechanism of translucent and shrunken maize endosperm.【Method】 The mutant M-E-479 of homozygous maize was used as experimental materials in our study. Through phenotypic identification, genetic analysis, main ingredients measurement and scanning electron microscopy, mapping population of M-E-479 was selected and map-based cloning technology was performed to locate the mutant gene.【Result and conclusion】 The result showed that the amount of fat increased, while the protein and starch decreased, and the starch grains changed in size, shape and space configuration in the mutant endosperm of M-E-479. The mutant gene is located between SSR markers bnlg1074 and umc1506 of chromosome 10 by using F2 population. Meanwhile, the genetic distance is about 3.6 cM and the physical distance is about 2.2 Mb. The results suggest that M-E-479 is a new translucent and shrunken maize endosperm mutant, and its mutant character may be controlled by a recessive single gene.