Abstract: Based on the data of concentration of anions,air quality index (AQI),temperature,humidity and rainfall from September of 2015 to August of 2016 at the scenic spot of Emei mountain (Mt.Emei),the seasonal variation characteristics of concentration of anions and their relationship with meteorological factors were analyzed,and a prediction model for concentration of anions in the Mt.Emei was established.The results show that concentration of anions has an obvious seasonal variation.The highest values appear in autumn,followed by spring and summer,and the lowest one appears in winter.They all reach the SGFA (Standard Grades of Forestry Aeration) secondary standard.The AQI,temperature,rainfall are the key factors influencing the concentration of anions in the Mt.Emei.The reason of the highest concentration of anions appearing in autumn is due to the suitable temperature,abundant precipitation,wet air,large biomass,and so on.The falling leaves of the deciduous and mixed forest,reducing biomass,less rainfall and dry air are the reasons for the lowest concentration in winter.The prediction model based on the S model is as follows:y=exp (1.4552/x+7.5988).Its prediction accuracy is good.R-square of the three-dimensional model is excellent with 1.It can reflect the rules between the concentration of anions and the interpretation parameters in the Mt.Emei.The prediction model based on the S model can forecast the concentration of anions.The three-dimensional model builds an analysis-forecast system and is more suitable for forecasting the concentration of anions in the Mt.Emei.