In forest ecosystems, understory vegetation and soil organic matter play an important role to enhance ecosystem stability and sustain ecological function. On the other hand, the understory vegetation competes with overstory for soil water and nutrients and thereby may reduce tree productivity in plantations. Although the removal of understory vegetation and organic matter may have an impact on stand growth and belowground condition, less is known of their effect, particularly on fine root phenology. Therefore, we investigated the effects of understory vegetation and organic horizon removal on litterfall production, soil properties, and fine root phenology in the Pinus rigida plantation. We removed understory vegetation biomass (20.2 Mg ha-1) and organic layer (38.6 Mg ha-1) in August 2015, and examined the litterfall production, soil physical and chemical properties, fine root phenology using an optical scanner method. Total yearly litterfall amount decreased about 31% after treatment. Soil pH and exchangeable Ca2+ increased, but available phosphorus decreased significantly from 15.7 to 5.44 mg kg-1- in the treatment plot (P<0.05). Total fine root area production in the treatment was lower in spring initially, but it started to exceed the control from early June, resulting in 3 times higher production in the treatment at the end of June. This study will improve our understanding of how the removal of understory vegetation and organic layer affects the forest ecosystem functioning as a carbon sink.