Abstract: In order to evaluate the interaction degree between red beds rock and water,the properties of slaking,swelling,softening,cementing and CBR are studied in laboratory;the method of rock water stability analysis is advanced;the engineering criterion of red beds rock water stability is established,including of slaking type,free swelling ratio,soft coefficient,cementation coefficient,California Bearing Ratio(CBR) soft coefficient.According to the water stability criterion,the red beds rock is classif...