Effect of inorganic fertilization on soil nutrient, soil structure and peanut yield was studied by a 20a’ long-term experiment in the Red Soil Ecological Experiment Station of Chinese Academy of Sciences. Results show that the peanut yield of inorganic fertilization treatments followed the order of NPK > NPKCa > PK > NP > NK. The difference among treatments was quite significant, showing peanut yield was significantly affected by the no-P treatment. besides slight decrease in soil total potassium, Inorganic fertilization increased the contents of soil total nitrogen, total phosphorus, available phosphorus and exchangeable potassium to some extents as compared with their initial values. Organic matter increased in all the treatments by 4.6~6.62 g kg^-1. Compared with long-term organic-inorganic fertilization, the inorganic fertilization significantly decreased the content of > 0.25 mm water-stable aggregates, increased the soil aggregate breakage rate by 9.38%~16.56%, and reduced the mean weight diameter by 0.15~0.18 mm. On the one hand, long-term inorganic fertilization improved soil nutrient contents and peanut yield, on the other hand it ruined the soil structure, which consequently affected soil nutrient availability and peanut yield. Long-term inorganic-organic fertilization might probably improve this situation.