183 maize inbred lines were planted in Guiyang according to a random block design to preliminarily study the genetic patterns of the content of crude protein， starch， neutral detergent fiber （NDF）， acid detergent fiber （ADF）， soluble sugar， and the in vitro digestibility of dry matter in maize. The content of crude protein， starch， NDF， ADF， soluble sugars， and the in vitro digestibility of dry matter in maize was determined. The Maize SNP 50 chip was used to genotype materials tested. Genome-wide association analysis （GWAS） with the mixed linear model （MLM） was performed. The results showed that 31， 61， 11， 36， 20， and 42 single nucleotide polymorphisms （SNPs） sites were identified to be significantly associated with the content of crude protein， starch， NDF， ADF， soluble sugars， and the in vitro digestibility of dry matter in maize （P<0.001）， with the explanation rates for phenotypic variation of 5.80%-11.40%，5.78%-11.38%，5.78%-7.85%，5.81%-10.37%，5.78%-7.35%，and 5.79%-11.33%， respectively. It was found that SYN6712， PHM1190.3， SYN7541， and PZE-104072386 belong to a pleiotropic locus. Among them， SYN6712， PHM1190.3， and SYN7541 on the chromosome 6 were significantly associated with the content of starch and the in vitro digestibility of dry matter， while PZE-104072386 on the chromosome 4 was significantly associated with the content of ADF and soluble sugars. The results of allele identification showed that the T/T genotype was an elite allele of SYN6712 and PHM1190.3， and candidate genes including Zm00001d03772， Zm00001d037386， Zm00001d037532， and Zm00001d051166 were identified. It will provide theoretical support for the further studies on the genetic mechanism of quality related traits in maize including the content of crude protein， starch， NDF， ADF and soluble sugars， as well as for the molecular markers assisted breeding.