This paper presents a Geographic Information Systems (GIS) based framework of fire risk assessment and emergency route planning for heritage buildings in historic centers. The framework addresses the specific challenges faced by heritage buildings, such as fragility, insufficient risk awareness, and inadequate emergency response. In the framework, potential risk factors are first identified and categorized through a literature review, forming a fundamental instrument for assessing the vulnerability of heritage buildings. Next, GIS technology is adopted to visualize the risk levels on spatial maps. Open-source route data is further collected and merged into a virtual prototyping engine to develop an emergency route simulation application. Specifically, a city-level navigable network is constructed to calculate the possible emergency routes between heritage buildings and fire stations using Dijkstra’s algorithm. The proposed framework is carried out with a case study of two heritage buildings (i.e., the Ruins of St. Paul's and Kuan Tai Temple) in Macao, which showcases that the framework can indicate quantitative fire risk levels and optimized routes to enhance fire safety and heritage conservation.