Abstract:Permanent sample plots were laid under fir forest in the 31°36′ latitude north and 102°67′ longitude east,between 3,400—3,700 metres above sea leval,in Miaro region western Szechwan. Four forest types were chosen for the sample plots:1. Abietum-sinarundinariosum,2. Abietum-hylocemicso,3. Abietum quercosum and 4. Abietum rhododendrosum. Observation began in 1960 and ended in 1964.changes in soil water,soil temperature,soil gas exchange(CO2 in the soil air),organic matter,leaching water(composition lysimetric water)and soluble substances(available nitrogen,phosphorus,potassium,soluble ferric oxide and ferrous oxide)and soil acidity were recorded.Their diagnostic velue for classification of the fir forest soils are discussed.