Abstract: In order to clarify the vertical distribution characteristics of soil available nutrients in Hunan tobacco-rice rotation area under long-term shallow tillage, the distribution characteristics of alkaline nitrogen (available nitrogen), phosphorus and potassium in different soil layers, the stratification ratios of soil available nutrients and their relationship with the depth of plough layer were analyzed based on 30 typical tobacco fields in this study. The results showed that the depth of plough layer in Hunan tobacco-rice rotation area was 8.2-16.4 cm, with a mean value of 12.6 cm. Soil available nitrogen, phosphorus and potassium contents were all decreased with the increase of soil depth. The contents of soil available nutrients in different areas were highest in 0-10 cm layers, decreased mostly in 20-30 cm layers, and serious deficit in 30-50 cm layers. The soil available nitrogen, phosphorus and potassium all showed significant stratification and surface aggregation, particularly for the soil available phosphorus. Soil available phosphorus and potassium were both significantly correlated with the depth of plough layer (y_P=97.04-4.42x, p<0.05; y_K=977.12-58.80x, p<0.01). In conclusion, the depth of plough layer in Hunan tobacco-rice rotation area was very shallow. And soil available nutrients had obvious surface aggregation phenomenon. So, it was necessary to deepen the plough layer, control the chemical fertilizer input and increase the organic fertilizer application according to local soil nutrient conditions.