Abstract: Objective To investigate the expression of miR-429 and its target gene heat shock protein A4L (HSPA4L) in sperms from asthenospermia patients. Methods Twenty semen samples from healthy and fertile adults and 20 semen samples from asthenospermia patients were collected, and normal sperm parameters were defined according to World Health Organization criteria. The expression levels of miR-429 and HSPA4L mRNA were determined by qRT-PCR, and the bioinformatics tool (Targetscan) was used to predict the target of miR-429. Luciferase reporter assay and transfection study were performed to confirm target gene of miR-429. The expression levels of HSPA4L mRNA and protein were further determined by qRT-CPR and Western blot, respectively. Results The motility and viability of sperms from asthenospermia patients were lower than that in control group, and miR-429 was up-regulated in sperms from asthenospermia patients. Bioinformatics analysis revealed that HSPA4L was a target of miR-429. Luciferase reporter assay and transfection study further confirmed that miR-429 suppresses the expressions of HSPA4L mRNA and protein via directly targeting HSPA4L 3′UTR. Results from clinical samples also demonstrated that HSPA4L mRNA and protein were down-regulated in sperms from asthenospermia patients and the expression level of miR-429 was inversely correlated with the expression level of HSPA4L mRNA (r=-0.725,P<0.05). Conclusion miR-429 is up-regulated in sperms from asthenospermia patients, and it may modulate the motility and viability of sperms via suppressing the expression of HSPA4L.