Karyotype analysis is by far the most common method used clinically to examine genetic information in infertile males. Its similar to examining the entire encyclopedia volume in a library to check if most of its volumes are missing, and it can check for a number of recognized genetic defects. However, the Y chromosome microdeletions, which are common in clinical practice, are too small to allow them to be distinguished in cellular karyotyping, so is it necessary to do Y chromosome microdeletion testing to further assess male fertility status? Data show that nearly 7% of men with infertility have Y chromosome microdeletions, with nearly 13% of azoospermia having microdeletions in the long arm of the Y chromosome and 3% to 7% of oligospermia having microdeletions. The AZFa and AZFb regions of the Y chromosome are the key to complete spermatogenesis. AZFc deletion is the most common type of Y chromosome microdeletion in clinical practice, and its clinical manifestations are diverse, including azoospermia, azoospermia or oligospermia. The clinical manifestations are diverse, ranging from azoospermia to normal sperm count but abnormal sperm morphology. The impact of different types of Y chromosome microdeletions on male fertility varies greatly, and since these microdeletions can be passed on to male offspring, it is necessary to perform Y chromosome microdeletions before assessing the fertility of male infertility patients and performing ART.