Abstract: Objective: To study the semen quality of healthy and fertile men in Tianjin, and explorethe factors affected semen quality. Methods: Semen assay was conducted on the World Health Organization's manual on semen analysis (4th)援The Olympus BX40 differ microscope was used to detect semen quality of 120fertile and healthy men aged 19 to 38 years. They had children within age of 1 year or let their sexsual partnerpregnancy within 3 months. Those factors including age, educational level, abstinence time, marital status,drinking, smoking, drinking tea or coffee were analysed. Results:淤 Sperm density of 17 (14.17%) men was< 20伊106 /mL. The sperm survival rate of 6 (5.00%) men was < 50%. The semen quality of 20 (16.7%) men didnot fully meet the standard.于There were not significantly difference in those semem paramenters among menwith different ages, different abstinence time，with or without drinking or smoking(P>0.05).盂Semen PH value was significantly different between men drinking coffee and men no drinking (P<0.05).榆Sperm density was significantly different between men drinking usually tea and men drinking infrequently tea(P<0.05).There were not significant differences (P>0.05) in those parameters such as grade (A+B) sperm rate and viability rate between two groups. Conclusions：Few parameters of semen quality could not meet the index of WHO 4thmanual in 120 fertility men. Age and abstinence time are not the risk factors of semen quality, but drinkingusually tea affect sperm density and coffee affect semen pH.

Key words: Fertility, Semen, Sperm count, Sperm motility