The reference value for microscopic examination of sperm concentration is 15×109/L. Sperm concentration consistently less than 15×109/L is considered oligospermia. The causes and significance of reduced sperm concentration can be categorized into five. 1. Testicular lesions: varicocele, or malformation of testis, tuberculosis, inflammation, gonorrhea, cryptorchidism, etc. 2. Vas deferens disease: obstruction of the vas deferens, or congenital absence of the vas deferens or immune sterility, etc. 3. Endocrine diseases: pituitary function, gonadal function, hypothyroidism or hyperfunction, etc. 4. Food effects: long-term consumption of cotton phenol, etc. 5. Others: harmful metal or radioactive damage, application of anticancer drugs, etc. If you want to monitor the sperm should go to the regular hospital for examination, if there is any abnormality, you should actively cooperate with the treatment and improve the quality of life with the help of professional doctors.