| ObjectiveIn order to provide the scientific data for preventing strategies , the prevalence characters of malaria in China , the relation of malaria and meteorological factors and a predicating model for forecsting of malaria have been studied. Methods1. Descriptive study. The data about malaria occurrence and climate changes from 1950 to 2001 in China have been collected and analyzed with software package of SPSS10.0 for Windows. The special maps of incidence rate have been established by using the technique of electronic map in MapInfo Professional5.5. The relationships of meteorological factors and malaria have been analyzed with correlations analysis of pearson. 2. Forecasting model of neural network. The forecasting model for malaria occurrence has been established by using the Neural Network Toolbox of Matlab6.1 software package. In the studies of forecasting model, the data of malaria and meteorological factors from 1994 to 1998 in Honghe State in Yunnan province have been chosen to analysis. The meteorological factors included average monthly pressure,air temperature,relative humidity,monthly maximum air temperature,minimum air temperature,rainfall,rainday,evaporation and sunshine hours. The established forecasting model also has been tested and verified by fact data of malaria.Results1. Malaria prevalence in China. (1) The malaria incidence rate during the years of 1950~2001 in China could be divided into three levels. The first level was presented during the years of 1950~1984, the general annual incidence rate was over 100 per 100 thousand. During the period of tine, there were three humps of incident rate, respectively at the year of 1954,1960 and 1970. From the year of 1970, the average incident rate was descended. The second level was presented during the years of 1985~1990. The average annual incidence rate was about 10 ~100 per 100 thousand. The third level was presented during the years of 1990 to present, the average annual incidence rate was below 10 ~100 per 100 thousand. In 2001, the rate was dropped to 1.99 per 100 thousand. (2) 147605 malaria cases and 220 death cases were reported from 1997 to 2001 in China. Average annual incidence rate and mortality rate were about 2.3941 per 100 thousand and 0.0036 per 100 thousand. The fatality rate was about 0.15 %. According to the number of malaria cases, the highest region was Hainan province. The second was Yunnan province. (3) During the years of 1994~1998, 184939 cases of malaria have been reported from 1228 of 2353 (52.91%) counties. Cumulative incidence rate was 15.17 per 100 thousand. The annual incidence rates of some counties (42%) were 1~10 per 100 thousand. According to the cumulative incidence rate, from the highest to lowest, the ranks of region were Motuo in Tibet , Ximeng, Yuanjiang, Wanding in Yunnan, and Baoting in Hainan and etc.2. Influence of meteorological factors. (1) 66% of cases of malaria were occurred at the areas where average annual temperatures were above 15℃ and the differences of annual temperatures were within 20℃. At the areas where average annual temperatures were over 20℃ and differences of annual temperatures were within 10℃, the incidence rate could reached to 994.91 per100 thousand. 94.89% cases of malaria could occurred in the areas where the average relative humidity were above 70%. Over 80% of counties which had the cases of malaria and 95.55% cases of malaria had the characteristics of distributed at the regions where annual rainfall were above 800mm, annual rainday were above 60 days. 86.17% cases of malaria occurred in the areas where annual evaporation were within 1000~2000mm, sunshine in a year were about 1000~2000 hours. (2) The positive relationships between some of meteorological factors and malaria were found. These factors included average annual air temperature(r=0.880, p<0.05),　relative humidity(r=0.988,p<0.01), annual rainfall(r=0.806,p<0.05) and rainday (r=0.920,p<0.01) respectively. 3. Neural network model. The BP network model has b...
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