Abstract: Air transport services across the Taiwan Strait are rapidly developing. Taiwanese airlines are therefore facing a critical decision as to whether to expand their scheduled services beyond saturated markets. The Taiwanese government is also concerned regarding airline operators' willingness to enter new markets for next-round negotiations concerning traffic rights. This study proposes an Analytic Hierarchy Process (AHP) framework for Taiwanese airlines based on a market opportunity analysis (MOA) to evaluate the determinants of potential service expansion. A novel rank pair-wise comparison (RPC) is used to measure the relative weights among determinants. It is found that service provision for Taiwanese merchants is the most vital factor. Flight quotas and allowed time slots also affect airlines' willingness to expand operations. Other determinants depend on the individual airlines' development background and operating size. This study also evaluates twelve airports in mainland China using grey relational analysis (GRA) to rank the entrant priorities for additional scheduled services.