To determine the prevalence of sexual problems particularly premature ejaculation and erectile dysfunction among men working in factories of Dongguan city, using the self-rating scales like International Index of Erectile Function, and to investigate the characteristics or risk factors associated with these sexual problems in floating population through regression analysis.

In China, the floating population is a special group of people who work and live outside their hometowns and without residence cards of that area they reside. Sexual problems are common in floating population, majority of whom are in their sex active age. There is a lack of studies concerning these sexual problems, so we conduct this survey to investigate the sexual dysfunctions among men, especially the floating population, and to find out whether most of these sexual problems are related to their social lives, medical illnesses, and psychological status.

Inclusion Criteria:

• have reached 18 years old
• live in Dongguan more than 6 months
• floating population
• with or without residence card

Exclusion Criteria:

• younger than 18 years old
• live in Dongguan less than 6 months

male workers in several towns of Dongguan city