The contents of organic matter, nitrogen, phosphorus, potassium in different agricultural soils were analyzed to study the status and changes of these nutrients. The relationship between nutrient contents and cultivated years was also studied. The results indicated that compared with the results from the Second National Soil Survey, the contents of organic matter, total nitrogen and phosphorus were largely increased, which even increased by 120%, 160% and 364%, respectively, in greenhouse soils; while the potassium content was only increased by 17.5%. In comparison with those among different-used soils, the content of Organic Matter, Nitrogen, Phosphorus in greenhouse soil was higher than that in other used soils, while the content of potassium in greenhouse soil was lower than that in the soil of wheat/corn field and cotton field. The contents of Organic Matter, Nitrogen, Phosphorus, Potassium were respectively in the levels of > 20g·kg-1，> 1.2g ·kg-1，> 1.0 g ·kg-1，20-25 g ·kg-1 in greenhouse soil. The studies on the relationship between cultivating years and the contents of nutrients indicated that with the increasing of cultivating years, the contents of Organic Matter, Nitrogen, Phosphorus in greenhouse soil were increased, and the greatest levels of them appeared after 9.6, 8.9, and 114 years of cultivation, respectively. Thereafter the contents of nutrients were found to decrease. The decrease of greenhouse soil quality has been a very prevalent problem after a long farming time.