On 27th of July 2015, the Republic of Kazakhstan has officially joined the WTO, and as a member of Eurasian Economic Union (EAEU), Kazakhstan and other member states have signed an agreement to establish a common market and achieve a unified common tariff system inside of this Union. Under such circumstances, Kazakhstan undoubtedly will produce a certain economic impact on the EAEU member states in cases of fulfilling the obligations and agreements signed within the framework of the WTO. Therefore, based on a comprehensive summary of the obligations and agreements in the fields of agriculture, non-agriculture products and services after Kazakhstan’s accession to the WTO, this paper found that the possible economic impact on the Eurasian economic union would include: The EAEU’s total tax revenue on imports will decline; Producers inside of Union will face more intensive competition pressure in Kazakhstan market; EAEU members will face a re-export competitive pressure from Kazakhstan’s market; Kazakhstan’s accession to the WTO will slow down the financial integration processes inside of the EAEU; Kazakhstan’s accession to the WTO will promote further reforms of the trade dispute settlement mechanism inside of the Eurasian Economic Union.