Abstract: Zhangs.hubu stone-pit in Baoan County is located in the mountain area.The workers' camps are 2-3 km away from the village.In a recent survey,in malaria peak season (June,July,August) An.anthropophagus accounted for 87.7% (1059/1207) of the total anopheline population and the average man-biting rate was 10.90,24.88 and 8.71 respectively.The sporozoite positive rate,the human blood index and the daily survival rate were 0.54% (3/554),1.0 and 0.803 respectively.The parasitaemia rate,the rate of gametocyte carriers,and the rate of p rsons with malaria history within 1-2 months were 45.5% (10/22),13.6% (3/22) and 50.0% (11/22),respectively.On average,the entomological inoculation rate A,B and C calculated by three methods were 0.084,0.665 and 0.215,respectively,indicating that the workers might get malaria infection if they stayed at the camp for 1.5-11.9 days.An analysis of the malaria onset time of the patients suggested that the time calculated from the inoculation rate A was closer to the real situation than those calculated from the inoculation rate B or C.The prevalence trend of malaria could be predicted through the monitoring of the entomological inoculation rate.