In order to effectively reduce the hazard of acid rain to ecosystems, buildings and human health in Rizhao City, provide the decision basis for the control of acid rain, based on the observation data of acid rain and pollutant emissions data in Rizhao during 2006 to 2012 years, the author analyzed the characteristics of climate change of acid rain and studied the effects of rainfall, wind, fog, marine aerosol and other conditions pollutants on the pH value of precipitation and acid rain frequency. The research shows that: (1) as a whole, acid rain frequency in recent 7 years in Rizhao was on the rise. The year and season change of its strength and frequency was obviously. Relatively summer and winter were heavier pollution seasons. (2) Rainfall, wind direction, wind speed and the fog had a greater influence on the frequency of acid rain. (3) The pH value of acid rain and SO_2, NO_2 emissions presented a significantly negative relationship. Especially in coastal areas, marine aerosol significantly impacted on pH.