One of basic problems of cryopedology the sallmoisture transfer in soil freeze-thawing processes.The special lawis up of the two times salt-moisture transfer affected by soil type

initial moisture content

salinity and temperature. emperatureis its driving force. Salt moves towards frozen layer with moisturefor soilwater po-tential falling in the freeze process

so salinity contentivencxeases in the frozen layer continuously. In the thawing process

salinity and moisture cumulated in the frozen soil layer move up again with evaporation

salinity of the surface layer increasing sharply. The resultof simulated experiment notonly proves the formation process of the soil salinization

but also provides theory for prevention and〔ure of soil salinization the freeze-thawarea of the North China.