Abstract: Objective To investigate the frequency and types of the major Y chromosome microdeletions in non-obstructive infertile males with azoospermia and severe oligozoospermia in Chinese. Methods Multiplex polymerise chain reaction (PCR) amplification was used to detect Y chromosome microdeletion in 203 non-obstructive infertile men, including 125 patients with azoospermia and 78 with severe oligozoospermia, as well as 100 fertile men in the control group. Results Among the 203 non-obstructive infertile cases, 22 (10.8%) carried a Y chromosome microdeletion and the frequencies of such microdeletions were 9.6% in azoospermia and 12.8% in oligozoospermia. The most frequent microdeletions were in the AZFc, and all the severe oligospermia were found microdeletions in the AZFc. No Y chromosome microdeletion was detected in the control group. Conclusion It is necessary to offer genetic screening and counseling to infertility men prior to intracytoplasmic sperm injection (ICSI) or in-vitro fertilization (IVF).