The magnetic phase transition of stage-2 CucCo1-cCl2GIC's has been studied using SQUID AC magnetic susceptibility. For 0.4 ≤ c ≤ 0.9 the system undergoes a phase transition at Tcland a reentrant spin glass transition at TRSG(<Tcl). For 0.9<c ≤ 0.93 the system undergoes a spin glass transition at TSG from the paramagnetic phase to the spin glass phase. No phase transition is observed for c = 1 at least above 0.3 K. The nature of reentrant spin glass phase and spin glass phase is examined from the frequency dependence of absorptionX″.