The　whispering　gallery　mode　(WGM)　microcavity　has　a　high-quality　factor　and　small　mode　volume,　for　the　property　of　confining　photons　in　a　small　volume　for　a　long　time,　which　enhances　the　light-matter　interaction.　Combining　with　quantum　dots　that　act　as　gain　medium,　it　can　realize　low-threshold　and　narrow-linewidth　microlasers　with　excellent　performance.　However,　achieving　conventional　whispering　gallery　mode　lasers　still　requires　complex　preparation　conditions.　Here,　we　report　a　narrow　linewidth　whispering　gallery　mode　lasing　from　all-inorganic　perovskite　quantum　dots　(CsPbBr3　QDs),　illustrating　facile　and　cost-effective　properties.　CsPbBr3　QDs　with　excellent　properties　were　synthesized　by　hot　injection　method　and　used　as　gain　media　for　lasers,　and　microspheres　as　optical　resonators.　The　whispering　gallery　mode　laser　with　a　quality　factor　Q　of　4791　and　a　narrow　linewidth　of　0.11　nm　was　obtained　at　room　temperature.　The　WGM　microlaser　achieved　by　this　paper　could　be　a　great　application　prospects　in　biotechnology.