Mobile markets in ASEAN have been steadily developed and expanded as reflected in mobile penetration rates. The 4G mobile subscribers are projected to grow steadily in line with market expansion and investment made by service providers completing for subscribers. To effectively connect all ASEAN countries, the Interconnection (IC) Charge is one of the most important issues in development of ASEAN telecommunications service. The objective of this paper is to study the IC rates of ASEAN countries. A Comparison of IC termination rates for mobile services in ASEAN is provided in this paper. An analysis of the IC for Thailand is focused in this research.