What to do if i have a problem of many times urination in evening (8-10)times (my age 30),what is the cause?

See a urologist: Aaron, frequency of urination is a common problem among men. It can be caused by stress, infection, an enlarged prostate, poor bladder habits, a urethra stricture, abnormal urine production, a sexual disease, or cancer. A urologist is an expert in this problem and can provide advice on identifying a cause and finding a solution to your vexing problem. Best of luck.

Here are some ...: If peeing often only occurs in the evening as described, I would first look into lifestyle as a possible important contributing factor. To verify it, record a detailed oral intake & urine output diary serially x 2 days, which will reveal the fact of living. Next, get UA to see if SP Gr is low suggesting overdrinking or poor renal concentration; get serum creatinine and BUN to see how kidneys work.