This paper counted and analysed the number of counties affected bydebris flows and the county times of occurence for destructive debrisflows. The results are as follows

1. in 29 provincial (municipal) administrative divisions of China

771counties (cities) the debris flows occured in

among them Sichuan Pro-vince is the most; 2. there are 92 cities or towns above couny-level suffered from debrisflow disasters

nevertheless

Sichuan makes up 40% of the total; 3. according to statistical data (1901-1985)

the destructive debrisflow occured for 18 county-times annually in China

but during the pe-riod of 1901-1950 for 10 and of 1951-1985 for 29. Sichuan is over 50% ofthe average. 4. based on the partial statistical data

the death number in annualaverage caused by debris flow was 117 and 179 before and after liberationrespectively; annual average number of houses destroyed were 60 and 1590before and after liberation. This paper discussed the debris flow harmsto factory

mine

highway

railway

course

military

hydropower sta-tion

irrigation and water conservancy

as well as tourist trade

etc.