BackgroundIn the worldwide, each year registered about 357 million new cases of sexual transmitted diseases.39 % of all infectious diseases were STI diseases in Mongolia in 2013 and which also 56.8 % of totalinfectious diseases Dornod province.ObjectiveTo investigate sexual transmitted diseases among the population of Dornod province and its commonrisk-factors.Materials and MethodsIn the survey were chosen 600 persons which is aged from 15 to 64 by random selection methodand divided into 6 cluster and each cluster had 100 persons. In the survey attended 300 male, 300female.ResultsThe survey respondents were married 59.1%, 50.7% of the employed, and 49.3% of the unemployed.2,1% of the survey population has already been tried drug abuse, but in the group of age 15-24,indicate level of the knowledge about drug abusing is very low which is 29,4%, a little or less knowabout drug abusing 35,6%, not know about drug abusing 35%. In other hand beverage usage levelwas very high which is 67% and 51,3% is using an alcohol in the last year constantly.Examination of specialized doctors 38.3% were suspected of sexual transmitted infections. Theyincluded laboratory testing.The 4.9 percent of total respondents had sexually transmitted diseases. It were syphilis 57.1%,gonorrhea 10.2%, trichomonasis 6.1%.The 83 percent of total respondents had sexual intercourse. The average age of first sexualintercourse was 18 ± 1 (95% CI 16.8 - 19.1), 7.1% had two or more sexual partners. Men had toused alcohol while sexual intercourse was 32.1 percent. Women were 49.2 percent and 38.5 percentof people infected with sexually transmitted diseases not use condoms during sexual intercourse.Conclusion1. One in 20 people surveyed, women aged 15-24 and men aged 35-44 have sexual transmissioninfection.2. Risk factors are had two or more sexual partners, had to used alcohol while sexual intercourseand using condoms during sex with casual partners are not enough.