To study whether the late-acting co-stimulatory molecules ICOS can suppress the apoptosis and sustain the survival and proliferation of T cells through the survivin pathway, ICOS signals deficient T-cells were infected with adenovirus carried survivin gene, other T-cells were given ICOS co-stimulatory signals, then infected with adenovirus carried dominant-negative mutant survivin gene. Apoptosis and proliferation were determined by TUNEL and CCK-8 respectively. The results show that engagement of ICOS signal increased the expression level of survivin significantly. Survivin can sustain co-stimulatory deficient T cells survival and suppress the apoptosis. Mutant survivin inhibits ICOS signal positive T cells survival and increase its apoptosis. Late-acting co-stimulatory molecules ICOS can suppress the apoptosis and sustain the survival of T cells through the survivin pathway.