Recently, the General Administration of Customs (GAC) has passed the Announcement of the General Administration of Customs on Issues Concerning Collection of Taxes on Maintenance Guarantee for Aviation Supplies (Announcement of the General Administration of Customs  No. 6) and the Announcement on Revising the Relevant Provisions on the Assessment and Determination of the Duty-paid Value of Aircraft under Operating Leases (Announcement of the General Administration of Customs  No. 8). The introduction of GAC Announcement No.6 improves the protection system of reliance interest of airlines and facilitates customs clearance and tax payment of aviation supplies with maintenance guarantee. At the same time, it increases responsibility of airlines, requiring them to properly keep and manage the related documents necessary for tax payment. GAC Announcement No.8 maintains and improves relevant provisions of previous announcements No.47 and No.55, and make its provisions more rigorous and practical.