The purpose of this study is to examine whether high risk groups tend to purchase high insured amount policy and whether the high insured amount lead to high loss ratio. The data on group injury insurance from a Property-Liability Company in Taiwan is analyzed from 2009 to 2010 by using structural equitation model. By comparing result 2009 and 2010, the implement the underwriting policy can make the adverse selection phenomenon of AD & D (accident death and dismemberment) insured amount disappear The rating system can also reduce the adverse selection phenomenon of MR (medical expense), DHI (daily hospitalization indemnity) effectively. The control the adverse selection can reduces the ex-ante moral hazard. The result of the study can be used to establish a continuous improvement quality management system.