Premature ejaculation is mainly diagnosed based on medical history, and an accurate classification is helpful in guiding clinicians to make accurate diagnosis and effective treatment of the disease. At present, there are also different knowledge and understanding of the clinical classification of premature ejaculation in the medical community. The relative consensus is to classify premature ejaculation into primary and secondary. The characteristics of primary premature ejaculation are: 1. rapid ejaculation occurs at the first sexual intercourse; 2. rapid ejaculation occurs almost every time of sexual intercourse and with every sexual partner; 3. the ejaculation latency is less than 2 minutes in most cases (90%). Secondary premature ejaculation is characterized by: 1. normal ejaculatory latency before the appearance of premature ejaculation; 2. premature ejaculation may be caused by other diseases: it may appear suddenly or gradually; 3. the patient ejaculates quickly at a certain stage; 4. it can be relieved or cured with the treatment of the primary disease. The European Society of Urology developed a new “Guidelines for the diagnosis and treatment of premature ejaculation” in 2009, which classifies PE into four categories: primary premature ejaculation, secondary premature ejaculation, natural variant premature ejaculation and premature-like ejaculatory dysfunction. The latter two have an intravaginal ejaculatory latency period (IELT) within the normal range and cannot be considered as diseases strictly speaking. Natural variant premature ejaculation occurs only occasionally and may be related to the frequency of recent sexual intercourse, novelty to the sexual partner and the sexual environment; premature ejaculation-like ejaculatory dysfunction may be related to the patient’s misperception.