Research on the size of Lyman Alpha Emitters (LAEs) provides important clues for understanding the formation and structural characteristics of young galaxies. In recent years, with the accumulation of high-resolution imaging observations, significant progress has been made in understanding the size characteristics of LAEs. A large number of studies have shown that LAEs generally exhibit a compact galactic morphology, with their effective radii significantly smaller than those of typical star-forming galaxies, displaying characteristics of high stellar mass surface density and high specific star formation rate (sSFR). This compactness is believed to be closely related to their low dust content, strong feedback activities, and early assembly stage. Despite certain differences among different samples, current results generally support the compact size characteristics of LAEs. Overall, existing studies indicate that LAEs represent a class of compact young galactic systems, and their morphological characteristics provide important observational constraints for understanding the early stages of galaxy formation.