The K-structures of the CSM wave functions in 164Er96 and 166Er98 were analyzed in the represention, the bases of which are characterized by the quantum numbers N,π,r,v,K,E1. The K-structure becomes complex as ω increases and the system becomes axially asymmetric. The calculation shows that the K-structure of the yrast band in 164Er96 is very similar to that in 166Er98, but the K-structure of the yrare band in 164Er96 is quite different from that in 166Er98.