Objective: To investigate the frequencies of AZF microdeletions in 137 infertile males with azoospermia and severe oligozoospermia from Jilin province of China and analyze the relationship between the levels of reproductive hormones and AZF microdeletions.Methods: A total of 160 infertile males were involved.Sperm concentration was measured according to standard methods, and karyotype analysis was performed on peripheral blood lymphocytes with standard G-banding.Multiplex polymerase chain reaction (PCR) amplification using nine specific sequencetagged sites (STS) were selected to detect Y chromosome microdeletions.Reproductive hormones levels, including plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E2), prolactin (PRL), testosterone (T) were measured using electrochemiluminescence immunoassay.Results: Chromosomal analysis showed that 23 (14.38%) of the chromosomal abnormalities were gonosomal in patients with Klinefelters syndrome (47, XXY).Among other 137 infertile males, AZF microdeletions were present in 8 (8.70%) azoospermic males, and 3 (6.67%) severely oligozoospermic males.The most frequent microdeletions were detected in the AZFc region, followed by AZFb+c, AZFb and AZFa.And there was no significant correlation between the AZF rnicrodeletion and the levels of reproductive hormones.Conclusion: These findings reinforce the necessity of AZF microdeletion testing among infertile males prior to employment of assisted reproduction techniques in Jilin province of China.