“Sun Tzu's Art of War"presents the most geopolitical thinking among ancient military books so far. The geopolitics-related chapters constitute a lot of proportion of the book, which demonstrates that Sun Tzu values the geopolitical importance in the war. The geopolitical thinking of“Sun Tzu's Art of War"mainly manifests in three levels: geo-strategy, geography, and terrain. Geo-strategy level involves diplomatic, economic, psychological, and military fields and hence forms Sun Tzu's geo-political diplomacy strategy, geo-economic strategy, geo-psychological strategy, and geo-military strategy; geographical level discusses the relationship between geographical situation, national defense construction, and military thinking respectively; terrain's level explores the tactics of a variety of terrain. In general, the main connotation of Sun Tzu's geopolitical thinking appears in getting the“favorable geography"and winning the war. The connotations still have their values and provide a lot of inspirations in the 21st century.