In Asian countries such as China, Malaysia, Pakistan, India, Taiwan, Korea, Japan and Hong Kong, ambient air total suspended particulates and PM_2.5 concentration data were collected and discussed during the years of 1998–2015 in this study. The aim of the present study was to (1) investigate and collect ambient air total suspended particulates (TSP) and PM_2.5 concentrations for Asian countries during the past two decades. (2) Discuss, analyze and compare those particulates (TSP and PM_2.5) annual concentration distribution trends among those Asian countries during the past two decades. (3) Test the mean concentration differences in TSP and PM_2.5 among the Asian countries during the past decades. The results indicated that the mean TSP concentration order was shown as China > Malaysia > Pakistan > India > Taiwan > Korea > Japan. In addition, the mean PM_2.5 concentration order was shown as Vietnam > India > China > Hong Kong > Mongolia > Korea > Taiwan > Japan and the average percentages of PM_2.5 concentrations for Taiwan, China, Japan, Korea, Hong Kong, Mongolia and Other (India and Vietnam) were 8, 21, 6, 8, 14, 13 and 30%, respectively, during the past two decades. Moreover, t test results revealed that there were significant mean TSP and PM_2.5 concentration differences for either China or India to any of the countries such as Taiwan, Korea and Japan in Asia during the past two decades for this study. Noteworthy, China and India are both occupied more than 60% of the TSP and PM_2.5 particulates concentrations out of all the Asia countries. As for Taiwan, the average PM_2.5 concentration displayed increasing trend in the years of 1998–1999. However, it showed decreasing trend in the years of 2000–2010. As for Korea, the average PM_2.5 concentrations showed decreasing trend during the years of 2001–2013. Finally, the average PM_2.5 concentrations for Mongolia displayed increasing trend in the years of 2004–2013.