Abstract: Additionality is the core concept and requirement of voluntary greenhouse gas emission reduction mechanisms.This article analyzes and summarizes the necessity,basic steps,and requirements for exemption from argumentation of additionality in afforestation carbon sink project.At the same time,it analyzes the natural and human risks that lead to re-release of the net anthropogenic greenhouse gases removal by sinks for afforestation carbon sink project,and proposes management strategies to address and reduce non-permanence risks in order to provide reference for the scientific development and effective management of afforestation carbon sink project.