Abstract: Objective: To assess the frequency of RBM gene microdeletion in men with idiopathic azoospermia and severe oligozoospermia,and to discuss the clinical significance of RBM gene detection.Methods: The RBM gene of peripheral blood leukocytes was detected by PCR technique in 22 azoospermia and 8 severe oligozoospermia patients.Results: RBM gene microdeletion was observed in 4 azoospermia and 2 severe oligozoospermia patients.Conclusions: As Azoospermic foctor deletion on Y chromosome long arm may be transmitted by vertical transmission,and result in infertile sons,detection of related genes is important for azoospermia and severe oligozoospermia patients before starting artificial insemination with the husband's semen and intracytoplasmic sperm injection in order to increase the eugenic birth rate.