With the aim to improve the quality of life of people and enable sustainable growth, cities of different sizes around the world are embracing the idea of Smart City with numerous innovative applications and services being rolled out.

This paper will present the current situation and trends of the market of Smart City.  We will take a look at the important role that the technology of Geographic Information System (GIS) can play in Smart City including building an indispensable Spatial Data Infrastructure (SDI) for various smart applications and services.  The SDI can support different development stages of Smart City, facilitate public engagement and crowdsourcing, better analyzing of real-time location based data, encourage exchange of innovative ideas, drive entrepreneurship and knowledge-based economy, etc.  As a result, an advanced and harmonious Smart City can be realized.