Urethral flow of transparent liquid physiological state can appear in the penis after erection, pathological state is generally considered to be caused by prostatitis. 1. In the physiological state, men in the penis erection sex, can appear in the urethra this transparent liquid, belong to the prostate fluid, can play a lubrication and promote the role of sexual intercourse, is a normal physiological phenomenon, do not need special treatment. 2. prostatitis attack, can make the prostate gland congestion and edema, its internal accumulation of more inflammatory substances, when urination or squeezed will lead to prostate fluid flow into the urethra, in the urethra will be found in the transparent liquid, chronic prostatitis, can appear the phenomenon of dripping white, you can go to the hospital as soon as possible. There may be other reasons for the urethral flow of transparent liquid, the patient needs to consult a doctor in time for examination and early treatment.