Normal spermatozoa are similar in shape to tadpoles with an oval head and thin mid-segment and a straight, non-curled, homogeneous tail that is thinner than the mid-segment. In semen examination, abnormal sperm can be seen with a pointed, conical head, irregularly shaped, large, small, or double-headed head, a thickened mid-section with cytoplasmic vesicles, and a thick, short, bifurcated, curled, or double-tailed tail. The head contains genetic material and its defects have a greater impact on fertility. Cytoplasmic vesicles larger than half of the sperm head imply immature sperm; tail curl may be related to zinc content and other tail defects may be associated with asymptomatic reproductive system infections. A single sperm may have multiple defects, and abnormal sperm morphology often coexists with oligospermia or poor sperm motility, but can sometimes be present alone. An increased sperm malformation rate often indirectly reflects testicular spermatogenic dysfunction and inevitably affects sperm fertilization ability. Evaluation of sperm morphology should address the entire sperm: that is, including the head, mid-section and tail. The sperm should be stained and observed. Only sperm with normal head, mid-segment and tail are normal; all sperm with a critical morphology are classified as abnormal. According to strict criteria, 15% or more of the sperm should have normal morphology. If less than 15% of the spermatozoa are normal, it is called teratozoospermia and can cause infertility. When teratospermia cannot be found for any definite reason after a thorough and detailed examination, it is called idiopathic teratospermia. When the sperm morphology is abnormal, it is not conducive to penetrating the cervical mucus and entering the uterine cavity and fallopian tubes. When the head is abnormal, most of them have no acrosome, which can lead to the inability of the sperm to fuse with the egg. The current sperm malformation rate examination has two limitations: First, the generation and significance of the type of sperm malformation is not well understood, and the effect of each type of malformation on fertilization may be different, while the semen analysis report often provides only the malformation rate without classification, thus affecting the judgment. Secondly, the current examination method is whole semen smear and staining after observation, which cannot distinguish whether the deformed sperm is live or dead sperm. Since sperm death may cause sperm deformation, especially when the percentage of dead sperm is high, the appearance of high sperm deformation rate will appear; and the extraction of high viable sperm will enable sperm to be energized and cause some morphological changes of sperm, which affects the judgment of whether the sperm morphology is normal. Therefore, the sperm malformation rate cannot be simply determined by the percentage, but should be determined by the doctor.