The time-dependent quantum wave packet method is used to investigate the dynamics for the Li2 molecule,and the time-resolved photoelectron spectra (TRPES) of the Li2 molecule are calculated. At the short delay time, the particular phenomenon of TRPES with four peaks is qualitatively interpreted in a dressed state picture by analyzing wave packet motion on light-induced potential (LIP). The significant difference in the electronic structure of E1Σ+g between the inner and outer tuing points has an impact on the TRPES. The control for the first excited state A1 Σ+u of the initial wave packet is discussed.