To evaluate the short-term effect of ambient air pollution on cardiovascular hospital admissions and capture the susceptible subpopulations in Wuhan, China, we adopted a generalized additive model to quantitatively analyze the influences of air pollutants on daily cardiovascular diseases hospital admissions and examine the influences of different subgroups. The largest significant effects for PM2.5, SO2 and NO2 on cardiovascular hospital admissions were observed at lag0, lag02 and lag02, respectively, and a 10 mu g/m(3) increment in concentration of PM2.5, SO2 and NO2 were associated with 0.87% (95%CI: 0.05%-1.7%), 3.41% (95%CI: -0.21%-7.17%) and 2.98% (95%CI: 0.66%-5.37%) increases in cardiovascular hospital admissions. Nearly linear relationships were found for NO2 and PM2.5 with cardiovascular hospital admissions, and the J-shaped exposure-response relationship was observed for SO2 with cardiovascular hospital admissions. NO2 might have independent health effects of PM2.5 on the population at risk. The effect estimates for PM2.5 and SO2 were not sensitive with the inclusion of the co-pollutant adjustment. The gender, age and seasonal specific association between three pollutants and cardiovascular disease didn't show obvious differences in the magnitude and trend of the effects except that the seasonal difference of SO2 was significant. This study showed that PM2.5 and NO2 had effects on cardiovascular diseases, and the multiple pollutants should be considered together in the hazard models. In addition, the government should remind the resident to protect themselves and wear masks to avoid the harmful effect of air pollution, especially for the susceptible population.