Salt transfer law for cotton field with drip irrigation under the plastic mulch in Xinjiang was analysed from three aspects: different postemergences and drip irrigation years, from different direction (vertical direction and horizontal direction), different soil texture. The results show that with the retardation of postemergences, the cummulation of salt in different soil layers increase in different extent. The accumulation of salt in vertical direction increase at the soil layers from 0 to 60 cm, but the one at the soil layers from 60 to 100 cm change a little. The accumulation of salt in horizontal direction at the center of open ground is more than any other position and the one under the drop point is least. As for different soil texture, the variation of salt accumulation in loam is more regular than that in the clay. The longer drip irrigation years, the more the accumulation of salt in cotton field.