Grade A sperm 4% is usually not normal, and usually greater than 25% grade A sperm is normal. According to the mobility of sperm usually can be divided into four grades, grade A is fast forward, grade B is slow forward, grade C is swinging in place, grade D is not moving in place. Normal sperm motility should be at least 50% of the sperm belonging to grade A+B, or 25% of the sperm belonging to grade A, so that the sperm vitality is considered normal. 4% of the sperm in grade A indicates that the sperm’s vitality has not reached the above standard, which is an abnormal situation, and at this time, it can be diagnosed as a decline in sperm vitality in general. There are many reasons for decreased sperm motility, such as reproductive system infections, prolonged abstinence, varicocele, etc. The harms of decreased sperm motility include affecting conception, affecting eugenics, and easily leading to preterm labor or miscarriage. When checking out the sperm activity appears to decline, the patient should be under the guidance of the doctor to further identify the cause of the disease, the cause of the treatment.