According to the data analysis of PM2.5 mass concentration from December 2013 to February 2018 in Jinan, the mean and maximum PM2.5 mass concentration in winter are the highest, followed by that in spring and autumn, and the lowest is in summer; PM2.5 mass concentration is the highest in January and December and the lowest in August; the mass concentration shows a significant decreasing trend year by year. There are significant differences in PM2.5 mass concentration under different wind directions and higher mass concentration appears in N and ESE (prevailing) wind direction, which, on the one hand, is related to the regional transport of pollutants, and on the other hand, is related to the special topography of Jinan. The study shows whether the pollution source is on the leeward or the windward side, it is likely to cause high-concentration pollution; especially in winter, the topography of mountain will also intensify the impact of temperature inversion, aggravating the pollution. The correlation study finds in winter, spring, and autumn, PM2.5 mass concentration is positively correlated with both relative humidity and mean total cloud cover, while negatively correlated with sunshine duration and its anomaly; in winter, it is positively correlated with mean temperature and its anomaly, maximum temperature, and minimum temperature, while negatively correlated with mean, maximum, and minimum atmospheric pressure; in spring and autumn, it is positively correlated with temperature anomaly; in summer and autumn, it is negatively correlated with daily precipitation, and as rainfall intensity increases, the washing effect on PM2.5 is more significant. The correlation among the above variables all passes the significance test of P equal to or lower than 0.01.