The appearance of pimples the size of a grain of rice on the penis, not accompanied by pain, itching may be sebaceous gland ectopic, warts, pearly papules and so on. 1. sebaceous gland ectopic: may be the penis local sebaceous gland abnormal hyperplasia or clogging caused by the lesion area of the skin above the needle tip or rice grain size scattered small pimples, usually white or yellowish, not accompanied by pain, itching. 2. warts: mostly due to human papillomavirus infection, caused by the genital organs of a single or more granulomatous pimples, the initial period is not accompanied by pain, itching, the texture is relatively soft, the surface is relatively moist. 3. Pearl-like papules: are caused by physiological developmental variations, or circumcision, infection and other reasons. White, yellow or red papules appear locally on the penis in the form of pearls, usually not accompanied by pain and itching. In summary, the appearance of pimples on the penis of the size of a grain of rice, not accompanied by pain, itching, it is recommended to consult a doctor in a timely manner, follow the doctor’s instructions for further examination, with the help of the doctor to clarify the cause, and targeted treatment or treatment.