Abstract: The characteristics of inclusions in natural and synthetic gems are distinct due to their different forming mechanisms and can be utilized for distinguishing gems. In addition, intensive studies on inclusion characteristics of natural gems could identify them in their geographical origins and provide valuable information for gem synthetics. In this paper, synthetic gems (synthetic star sapphire and emerald) and natural gems from various locations including natural sapphire from Thailand and Australia, and natural aquamarine from Mufushan, Hunan Province, and Ailaoshan, Yunan Province, are selected for the comparative study of inclusions. Significant research results are achieved, providing important basis for identifications of natural and synthetic gems.