The anion content in different scenic spots in Taoyuandong National Forest Park,Yanling,Hunan,has been determined at different times and the air quality evaluated likewise.The result shows that the anion content in the park is 80 ̄ 1600times higher than that in the open air of the suburb or that in the indoor air of the urban districts,and that the air in the park is very clean.Based on these determination results,the author suggests developing tourism and setting up a sanatorium,and believes that the abundant anion resource in the p...