Objective To purify asprosin protein expressed in Escherichia coli expression system and to study its effect on cardiac function.Methods Coding sequence of asprosin was obtained from GenBank.Codon optimization was performed according to the codon preference of E.coli.After gene synthesized, recombinant plasmid was made.Asprosin was then induced and purified by Ni-affinity purification.The mouse model of impaired cardiac function was established by ligating and relaxing the left anterior descending coronary artery.30 mice were randomly divided into 3 groups: sham operation group (sham), cardiac dysfunction group (MI/R) and cardiac dysfunction plus injection of recombinant asposin protein group (MI/R+rAsp).The left ventricular function was detected by echocardiography to determine the improving effect of recombinant asprosin protein on cardiac function.Results After prokaryotic expression and purification, the purity of the target protein was higher than 95%, and the endotoxin content was less than <0.1 EU/μg protein, which was suitable for cell and animal studies.After the recombinant asprosin protein was given, the left ventricular function of the mice was improved significantly (P<0.05).Conclusions Asprosin acts as a myocardial protective molecule to improve cardiac function.