In this study, the activity concentrations of (210)Pb and (210)Po on the 22 daily air filter samples, collected at CTBT Yellowknife station from September 2015 to April 2016, were analysed. To estimate the time scale of atmospheric long-range transport aerosol bearing (210)Pb in the Arctic during winter, the mean transit time of aerosol bearing (210)Pb from its origin was determined based on the activity ratios of (210)Po/(210)Pb and the parent-progeny decay/ingrowth equation. The activity ratios of (210)Po/(210)Pb varied between 0.06 and 0.21 with a median value of 0.11. The aerosol mean transit time based the activity ratio of (210)Po/(210)Pb suggests longer mean transit time of (210)Pb aerosols in winter (12 d) than in autumn (3.7 d) and spring (2.9 d). Four years (210)Pb and (212)Pb monitoring results and meteorological conditions at the Yellowknife station indicate that the (212)Pb activity is mostly of local origin, and that (210)Pb aerosol in wintertime are mainly from outside of the Arctic regions in common with other pollutants and sources contributing to the Arctic. The activity concentration ratios of (210)Pb and (212)Pb have a relatively constant value in summer with a significant peak observed in winter, centered in the month of February. Comparison of the (210)Pb/(212)Pb activity ratios and the estimated mean (210)Pb transit time, the mean aerosol transit times were real reflection of the atmosphere transport characteristics, which can be used as a radio-chronometer for the transport of air masses to the Arctic region.