〔Abstract〕 Abstract Objective To enhance the solubility expression of carbonyl reductase ChKRED20 and investigate its enzymatic properties. Methods The ChKRED20 gene was synthesized and transformed into Escherichia coli BL21(DE3) for heterologous expression. The solubility of the protein was evaluated by adding or removing His⁃tag ,changing its position , and adjusting the induction conditions. Further optimization was performed by varying the in⁃duction time , temperature and IPTG concentration. Subsequently , the enzymatic properties of the recombinant en⁃zyme were examined. Results The ChKRED20 was cloned within the Escherichia coli system to achieve soluble protein expression. This was achieved by removing the His⁃tag and optimizing expression conditions. Compared to by 0. 77 and 1. 28 times , respectively. The optimal temperature and pH for enzyme activity were 55 ℃ and 8. 0 ,respectively. Furthermore , the enzyme demonstrated good adaptability in higher temperature and alkaline environ⁃prove the soluble expression of ChKRED20 in Escherichia coli.