Through test data from Anduo Section of Qinghai-Tibet railway,this paper discusses and analyzes the characteristics of temperature and the permafrost upper limit change of the subgrade that has adopted geogrid measures and piece of rocks for the foundation treatment on the permafrost swamp.

The soil distribution pattern in small micro scale was saline marsh-alkaline meadow soil-shallow columnar sodic alkaline soil-white crust sodic alkaline soil-blown soil.