Through a study on soil aggregate composition,nutrient status and enzymatic activity under mixed forest of Chinese fir Fokienia hodginsii and pure stand of Chinese fir,the results indicated that,compared to pure stand,the soil under mixed forest has more big aggregate,a higher level in porosity and penetrability,and a better structural property.The content of soil organic matter,total nutrition and available nutrition,and the nutrient conserving capacity are higher under mixed forest than that under pure stand.The activity of hydrolyzeable enzymes and oxidized deoxidized enzymes were higher,and the soil fertility has increased to a certain extent under mixed forest.It concluded that the mixed stand is capable of being self rich in soil fertility,and deserves widely spreading.