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.