Abstract: An investigation on hookworm infection was pursued by fecal examination. Fifteen townships in 5 counties (cities) were randomly sampled for the survey. A total of 4 846 out of 7 985 persons were found to infect with hookworm by Kato Katz method and test tube filter paper cultivation method. The overall infection rate was 60.9%, and the rates in Han, Li, Miao, and Hui nationalities were 47.8%, 75.5%, 87.3% and 54.3%, respectively. A trend of increase of incidence with age was indicated, except for age group above 70. The incidence in peasants was higher than in other occupations. Prevalence of the infection in rural area was higher than that in urban, township and coastal areas. 75.1% of the infected persons harbored simple Necator americanus and 1.7% simple Ancylostoma duodenale , as shown by hookworm larva cultivation. The mixed infection rate was 23.2% ( N.a.∶ A.d . = 4.37∶1). The result shows that Hainan Island is an endemic area of both species of hookworm with Necator americanus as the main species.