Abstract. Boreal peatlands are an important natural source of atmospheric methane (CH₄). Recently, boreal peatlands have been experiencing increased nitrogen (N) availability and decreased moss production. However, little is known about the interactive effect of moss and N availability on CH₄ emissions in boreal peatlands. In this study, the effects of moss removal and N addition (6 g N m⁻² yr⁻¹) on CH₄ emissions were examined during the growing seasons of 2011, 2012 and 2013 in a boreal peatland in the Great Hinggan Mountain of northeast China. Notably, the response of CH₄ emissions to moss removal and N addition varied with experimental duration. Moss removal and N addition did not affect CH₄ emissions in 2011 and 2012, but respectively reduced CH₄ emissions by 50% and 66% in 2013. However, moss removal and N addition did not produce an interactive effect on CH₄ emissions. Consequently, moss removal plus N addition had no effect on CH₄ emissions in 2011 and 2012, but decreased CH₄ emissions by 68% in 2013. These results suggest that the effects of moss removal and N enrichment on CH₄ emissions are time-dependent in boreal peatlands, and also imply that increased N availability and decreased moss growth would independently inhibit CH₄ emissions in the boreal peatlands of northeast China.