The methods to determine non-obstructive azoospermia and obstructive azoospermia are as follows: 1. Physical examination: touching the texture, size and vas deferens of the testes, if the testes are very small, the size of a soybean or the size of a broad bean, suggesting azoospermia due to loss of spermatogenic function of the testes, called non-obstructive azoospermia; if the size and texture of the testes are normal and the vas deferens are not retrieved, it is called congenital unilateral vas deferens or bilateral vas deferens. obstructive azoospermia caused by inaccessible ducts; 2. Testicular biopsy: the patient’s testes are well developed and textured, and the testes are examined for the presence of sperm in the testes through minimally invasive aspiration biopsy of the testes; if there is a large number of sperm in the testes but no sperm in the semen, it is called obstructive azoospermia, and then further examination is performed to clarify the site of obstruction; if there is no sperm in the testes, it is called non-obstructive azoospermia.