Cultural sustainability is about the continuation of natural and human resources. With such continuation, heritage is built up and is transmitted through forms, words and images. By then, heritage becomes sustainable, and is made accessible to everyone. In the process of mapmaking, the experiential spaces is re-created by the mapmakers and re-presented to the readers by the means of the descriptive texts, and the perceivable pictures. More than accessible, green mapmaking is a participatory one that involves anew understanding, exploration and discussion of green spaces in our immediate environment. This paper will offer an interpretive reading of green mapmaking in the case of Hong Kong. As part of a global green mapmaking movement, first initiated by Wendy E. Brawer in Green Apple Map of New York City (1992), Green Map Hong Kong is underway in its early stage. Still, this paper is by no mean product or its kind; rather, it aims to explore the possibility of green mapmaking in the field of sustainable heritage. Extend beyond the function of spotting green spaces of the present, the act of green mapmaking can go further to include green spaces in historical maps and/or reconstruction of historical maps, i.e. (old-) mapmaking. A number of historical maps in publications like New Peace County: A Chinese Gazetteer of the Hong Kong Region (1983), Mapping Hong Kong: A Historical Atlas (1992), and Mapping Hong Kong (2000) would be studied. By comparing the green mapped and green mapping ones, such as urban and rural areas, countryside, parks, villages, etc. the researchers can evaluate differences and investigate changes of cultural heritage over time.