This study was aimed to investigate the protective effects of ginsenoside Rg1 on 8-methoxypsoralen(8-MOP)/Ultraviolet A (UVA)-induced premature senescence in human fibroblasts, and the underlying mechanism. We established a stress-induced premature senescence model by 8-MOP/UVA irradiation. The aging condition was determined by histochemical staining of senescence-associated β-galactosidase (SA-β-gal). Relative telomere length was calculated by the ratio of the amount of telomere DNA versus single copy DNA by real-time polymerase chain reaction, and protein levels of p-P53, p21(WAF-1) and p16(INK-4a) were estimated by Western blotting. Compared with the 8-MOP/UVA treatment group, we found that the irradiated fibroblasts pretreated with ginsenoside Rg1 demonstrated a decrease in the expression of SA-β-gal, a downregulation in the level of senescence-associated proteins, and a deceleration in telomere shortening. Taken together, these results suggest that ginsenoside Rg1 significantly antagonizes premature senescence induced by 8-MOP/UVA in fibroblasts.