Few studies were conducted to evaluate health effects of acute exposure to PM 2.5 and daily mortality in Asian countries due to lack of large-scale PM 2.5 monitoring data. We conducted a time-series study to examine the associations of short-term exposure to four common air pollutants (PM 2.5 , PM 10 , NO 2 , and SO 2 ) and daily mortality in Ningbo, Zhejiang, China. We used generalized addictive model (GAM) to estimate relative risks (RRs) and 95% confidence intervals (CIs) for the association of these four air pollutants with daily mortality. The study included 9365 people in the 2-year study period from 2014 to 2015. SO 2 were significantly associated with risk of NAD, RD, and CD mortality with RRs of 1.034 (95% CI 1.004, 1.064), 1.067 (95% CI 1.010, 1.127), and 1.049 (95% CI 1.001, 1.098), respectively.PM 2.5 and PM 10 were significantly associated with risk of death from NAD mortality in warm season. Similar associations were observed for PM 10 (RR = 1.056, 95% CI 1.004, 1.111) and risk of CD mortality. The study provides further evidence that short-term exposure to PM 2.5 , PM 10 , NO 2 , and SO 2 are associated with increased risk of daily mortality.