Given its adverse health effects, particulate matter (PM) pollution has become a critical public policy issue in Northeast Asia. As concerns about PM pollution increase, so does the interest in identifying its origins, including trans boundary pollutant sources. Employing the daily average PM10 concentration level data from Beijing, Shanghai, and Seoul in 2014–2016, we estimate the direction and extent of the spillover effect of the PM10 density between China and Korea. Estimation outcomes suggest that the PM10 density levels in Beijing and Shanghai are Granger causes of the PM density in Seoul, but not vice versa.That is, the PM 10 density in Seoul increased by 0.13 and 0.133 ppm in response to the 1ppm increase in the PM10 density in Beijing and Shanghai on the previous day, respectively.The cross-border spillover effect from Beijing decreased by 0.076 ppm from May to October when the air flow hindered the PM10 sources generated in Beijing from reaching Seoul.