The last two times the semen was a bit yellow and smelly may be caused by prostatitis, seminal vesiculitis, orchitis and other factors. 1. Prostatitis: not paying attention to physical hygiene, drinking and smoking for a long time and other factors, may induce prostatitis, so that inflammatory substances in the prostate fluid, due to the prostate fluid is an important part of the semen, will lead to semen yellow, smelly, may also be accompanied by perineal swelling and pain, urinary frequency, urinary urgency and other symptoms. 2. Spermatitis: It may be related to the infection of neighboring organs, which may cause inflammatory substances in the seminal vesicles, which will make the semen a bit yellow and smelly, and may be accompanied by ejaculatory pain, and in severe cases, it may cause hematospermia. 3. orchitis: may be related to bacterial infection, will make the testicles there is inflammatory infection, will lead to semen yellow, smelly, may also be accompanied by scrotal swelling, pain and other symptoms, can lead to male infertility in serious cases. The last two times semen is a little yellow and smelly, there are many reasons, it is recommended to consult a doctor for examination and treatment to avoid adverse effects.