The Working Group Meeting in 2021 Session 1 for the EANET (WG2021-1) was convened, virtually, from 20-22 April 2021. Around 70 participants, including members from the EANET participating countries, namely Cambodia, China, Indonesia, Japan, Lao PDR, Malaysia, Mongolia, Myanmar, Philippines, Republic of Korea, Russia, Thailand, and Vietnam, joined the Session. The United Nations Environment Programme (UNEP) and the Asia Center for Air Pollution Research (ACAP), which serve as the Secretariat and the Network Center (NC) for the EANET, respectively, and the AIT RRC.AP were also present at the meeting.