Abstract: In order to promote the growth of mid-aged Pinus elliottii forest, the influence of different fertilizing levels of formula fertilizer was studied on the growth, the soil and cost-benefit of 9 year-old Pinus elliottii plantations in the northern part of Hunan, China. The results showed that, 3 years after fertilization, the increment of DBH, height, individual volume and the stand volume, and the fertilizer benefit of different fertilization treatments were higher than that of the contrast in different degrees, 700 g/tree had the biggest role for the growth of Pinus elliottii. 2 years after fertilization, the soil nutrient was improved than before, the soil pH value of different layers decreased, organic matter and available K content increased. Available N content increased dramatically, and the increase in the upper layer was higher than that in the lower one. Available P decreased in different degrees, and reduction in the upper layer was lower than that in the lower one. The proper application of fertilizer could promote the growth of Pisolithus tinctorius, and 7 months after fertilization, the number of Pisolithus fruiting body generally increased with the increase of the fertilizer in 100-800 g/tree. Fertilization once in middle-aged slash pine plantations could increase the yield and benefit of per unit area, the best fertilizing amount was N-P-K fertilization of 700 g/tree.