HAD-like hydrolase plays an important role in regulating plant growth and development and responding to phosphorus deficiency stress. Based on the genome-wide expression profile of cotton seedlings under low phosphorus stress in the early stage of our research group, related genes were excavated and their preliminary expression analysis was conducted. Genomic DNA and cDNA sequence of the gene were cloned and analyzed by bioinformatics method. Fluorescence quantitative PCR (qRT-PCR) were used to detect the changes of gene expression in root, stem, leaf and flower tissues.The relative expression patterns of GhPS2 under low phosphorus stress(0,4,12,24 and 72h) were analyzed by qRT-PCR technology.The results showed that: (1)GhPS2 gene of G. hirsutum L. was successfully cloned, and the full length of the open reading frame of the gene was 813bp, encoding 270 amino acids and containing 3 introns. Analysis revealed that this gene sequence belonged to the HAD family, with a conserved structure named PUT-Phosphatase. (2) Sequence alignment and evolution analysis showed that the similarity of GhPS2 to other cotton varieties PS2 and durian PS2 was 93% and 83.15%, respectively.（3）The results of qRT-PCR showed that GhPS2 gene was predominantly expressed in roots, followed by stems and flowers, with the lowest expression in leaves. The relative expression of GhPS2 gene was the highest in the roots treated with low phosphorus for 4 h, and it was 16.66 times that of suitable phosphorus treatment at 72 h under low phosphorus stress.This study demonstrated that GhPS2 gene belongs to low phosphorus stress response gene and may be involved in Gossypium hirsutum L. response low phosphorus stress.