Objective To study the correlation between demographic characteristics, and moderate or severe oligoasthenospermia and obstructive azoospermia.Methods Clinical data of 5 411 cases, who received IVF-ET or ICSI treatment in the Second Affiliated Hospital of Kunming Medical University of reproductive medicine, were retrospectively collected from January 2005 to December 2015. Three groups were divided based on the type of abnormal semen. 534 cases were in severe oligoasthenospermia group, 174 cases were in azoospermia group, 4 703 cases were in normal group. Demographic characteristics were compared between the three groups, which including age, duration of infertility, education, occupation, body mass index and nationality. Logistic regression model was used to analyze the correlation between the above factors and abnormal semen.Results (1) The prevalence of azoospermia in age younger than 30 years old was 5.5% which was statistically higher than other age groups; prevalence of oligoasthenospermia and azoospermia was 15.6% and 7.1% among people with ≥15 years of duration of infertility, which were statistically higher than other groups. Prevalence of oligoasthenospermia among people with primary school was 6.6%, which was significantly lower than other group. Prevalence of azoospermia among people high school and University and above group was 3.1% and 1.7% respectively which was significantly lower than other groups. Prevalence of azoospermia among workers and peasants was 4.2% which was significantly higher than other occupation group. The prevalence of oligoasthenospermia in Naxi nationality was 16.9%, prevalence of azoospermia in Dai nationality was 7.5%, which was higher than that of Han nationality. (2)With age increasing, the possibility of azoospermia was decreasing, that is, age was a protective factor for azoospermia (P＜0.05, OR=0.78). The possibility of oligoasthenospermia and azoospermia was increased with duration of infertility prolonging, that is , it was a risk factor for oligoasthenospermia and azoospermia (P＜0.05, OR=1.23; P=0.03, OR=1.05). The possibility of azoospermia was decreased with education elevating, that is, education was a protective factor for azoospermia(P＜0.05, OR=0.62). Naxi nationality was a risk factor for oligospermia and asthenospermia in comparison with Han nationality (P=0.03, OR=1.98).Conclusion Age was a protective factor for azoospermia. The possibility of azoospermia was decreased with age increasing, and the highest prevalence was among young people. Duration of infertility was a risk factor for oligoasthenospermia and azoospermia. The possibility of oligoasthenospermia and azoospermia was increased with duration of infertility prolonging. Prevalence of oligoasthenozoospermia was higher among people with higher education, and prevalence of azoospermia was higher among less educated people. The prevalence of azoospermia was the highest among workers and peasants. Education was a protective factor for azoospermia. The possibility of azoospermia was decreased with education elevating. There was significant difference of abnormal semen among minority and Han population, with higher prevalence of oligoasthenospermia in Naxi nationality and higher prevalence of azoospermia in Dai nationality, and the risk of moderate to severe oligoasthenospermia among Naxi nationality was 1.98 times than that of the Han nationality.