The identification and classification of expansive soils is the problems that should be firstly solved in construction in expansive soil region. The existing approach to identification and classification of expansive soils has been evaluated. The indices that can reflect and characterize swell-shrink mechanism and property were analyzed. The analysis indicates that 5 indices such as liquid limit

plastic limit

clay particles

free swell ratio

swell-shrink total ratio can reflect and characterize swell-shrink mechanism and property; hereby these 5 indices have been suggested as identification and classification indices of expansive soils; and a new approach of 5- indices including liquid limit

plastic limit

clay particles

free swell ratio

swell-shrink total ratio

for identification and classification of expansive soils has been established. The new approach to identification and classification of expansive soils has been validated and it has been shown that the new approach is easy and reliable.