Abstract: Based on the remote sensing retrieval of PM2.5 data in the long-time series, the temporal-spatial pattern of PM2.5 as well as its variation and sources of pollution in China from 1998 to 2014 were revealed by using the Theil-Sen median trend analysis, Mann-Kendall test and correlation analysis methods. The results showed that PM2.5 concentration reached the annual average criterion value of 10  μg/m³ specified by the World Health Organization (WHO) in the land area of only 24.67% during the period from 1998 to 2014. PM2.5 concentrations were less than 10 μg/m³ mainly in the Qinghai-Tibet Plateau, Taiwan, northern Xinjiang, north of Inner Mongolia and northwest of Heilongjiang, while the average annual PM2.5 concentrations were greater than 95 μg/m³ mainly in southern Xinjiang and North China Plain. During the period from 1998 to 2014, the concentration of PM2.5 increased by an average of 3.91 μg/m³ and the maximum value was 39.1 μg/m³ in 61.84% of the national land area. Among them, the central and western regions and the North China Plain exhibited a significant rising trend and some regions still show an increasing trend in the future. The driving factors of increase in PM2.5 concentration included natural factors and emissions from human activities, wherein it mainly came from the sand dust aerosol in the Taklimakan Desert in the southern Xinjiang, while those in the other areas mainly came from emissions in the human activities.