Abstract: To study the relationship between soil nutrients, ions and acidification of greenhouse pepper in Huai’an district of Jiangsu Province. Choosing the adjacent open field of wheat-pepper rotation as the reference, the pH, nutrient and ions in different continuous cropping years of pepper greenhouses soil were determined. Effect of continuous cropping years on soil nutrients and ions content, and the relationship between changes of nutrients, ions and soil acidification were studied through the correlation analysis, principal component analysis. Our results showed that with the cropping years increasing, soil pH was decreased and those values in continuous cropping years of pepper greenhouses soils were lower than those of the adjacent open field of wheat-pepper rotation. The contents of soil nutrients and ions in continuous cropping soil of hot pepper were higher than those of control, and the correlation of soil nutrients (organic matter, total N, total P, available K, Cl-, SO42-, NO3-) between pH was significant (P<0.05). Principal component analysis showed that the soil nutrients (organic matter, total N, total P, available K, Cl-, SO42- and NO3-) in continuous cropping soil could affect the acidification level of soil. Therefore, continuous cropping using pepper will cause soil acidification, the accumulation of soil nutrients might be the main reason of the acidification in pepper continuous soil.