Abstract: The sediment and overlying water of Sancha Lake were collected in the spring and autumn of 2017 to study the diversity of glucose dehydrogenase gcd gene and its relationship with environmental factors. High-throughput sequencing of gcd gene from the genomic DNA in the sediments was carried out to evaluate the diversity in gcd and associated community characteristics and to analyse the correlations between the gcd gene diversity indices and environmental factors. The results showed that:(1) from the 12 samples, 219, 778 valid sequences were obtained, and the classification annotation suggests 6 Phyla, 9 Classes, 15 Orders, 29 Families, 46 Genera, and 610 operational taxonomic units (OTUs), primarily Proteobacteria (25.10%-98.85%) and Acidobacteria (0-3.99%). (2) The phylogenetic tree of gcd gene sequences exhibits two branches and four sub-branches, and the gene sequences primarily attributed to orders Rhizobiales, Burkholderiales, Oceanospirillales, Pseudomonadales, and Acidobacteriales. (3) The gcd gene diversity were all higher in spring than in autumn, increasing from the lake center to the dam to the lake tail. In terms of the community composition of gcd-harboring bacteria, seasonal variation had a small effect on sampling sites L1, L2, L3, and L5, but had an appreciable impact on the sites L4 and L6. (4) The diversity indices of gcd gene were significantly correlated with ρ(DO), w(TP), w(HCl-P), and ρ(DTP). The OTU composition and distribution of gcd gene were significantly correlated with ρ(DO) and ρ(DTP). Our study indicated that the gcd gene in the sediment of Sancha Lake is highly diverse, with heterogeneous composition and distribution, which had great effect on ρ(DTP).