The Paris Agreement established a global stocktake mechanism that aims to bridge the gaps between goals and global visions，and between progress and action targets. In the recent negotiations on the implementation mechanism of the Convention on Biological Diversity，great attention has been paid to whether and how to strengthen the implementation through the global stocktake or review. By analyzing the formation，framing elements and the latest progress of the global stocktake，also taking into account of the ongoing first-round global stocktake under the Paris Agreement，this paper identifies challenges for the implementation of the global stocktake，including a lack of timeliness and integrity of input information，the uncertainty of conclusion because of the wide information inputs，and the deficiency of comprehensive，balanced and effective outcomes. It is suggested that the global stocktake should start from promoting the implementation，focus on identifying problems and proposing practical solutions，adhere to the demand-oriented information input，and uphold the comprehensive，balanced and efficient principles of stocktake process.