Submitted to 1 DOI: 10.1002/((please add manuscript number)) Article type: Communication Observation of Various and Spontaneous Magnetic Skyrmionic Bubbles at Room- Temperature in a Frustrated Kagome Magnet with Uniaxial Magnetic Anisotropy Zhipeng Hou*, Weijun Ren*,Bei Ding*, Guizhou Xu, Yue Wang, Bing Yang, Qiang Zhang, Ying Zhang, Enke Liu, Feng Xu, Wenhong Wang,Guangheng Wu, Xi-xiang Zhang, Baogen Shen, Zhidong Zhang Dr. Z. P. Hou, B. Ding, Y. Wang, Dr. Y. Zhang, Dr. E. K. Liu, Prof. W. H. Wang, Prof. G. H. Wu, Prof. B. G. Shen Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China E-mail: wenhong.wang@iphy.ac.cn (W. H. Wang) Dr.W. J. Ren, Dr. B. Yang, Prof. Z. D. Zhang Shenyang Materials Science National Laboratory, Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016, China E-mail:wjren@imr.ac.cn (W. J. Ren) Dr. G. Z. Xu, Prof. F. Xu School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China Dr. Qiang Zhang, Prof. X. X. Zhang King Abdullah University of Science and Technology (KAUST), Physical Science and Engineering (PSE), Thuwal 23955-6900, Saudi Arabia [*] Z.P.H, W.J.R, and B.D contributed equally to this work. Keywords: skyrmionic bubbles, topological spin textures, kagome magnet, Fe 3 Sn 2 , spintronic devices The quest for materials hosting topologically protected nanometric spin textures, so-called magnetic skyrmions or magnetic skyrmionic bubbles, continues to be fuelled by the promise of novel devices. [1-5] The skyrmionic spin textures have been mostly observed in non- centrosymmetric crystals, such as the cubic chiral magnets MnSi, [6-9] (Mn,Fe)Ge, [10,11] FeCoSi, [12] Cu 2 OSeO 3 , [13-15] and also the polar magnet GaV 4 S 8 , [16] where Dzyaloshinskii- Moriya interaction (DMI) is active. A number of intriguing electromagnetic phenomena, including the topological Hall effect, [7] skyrmion magnetic resonance, [17] thermally induced ratchet motion, [18] and effective magnetic monopoles, [19] have been demonstrated to be closely related to the topologically nontrivial spin texture of skyrmions. These novel topological properties, together with nanoscale dimensions, a stable particle-like feature, and an ultralow threshold for current-driven motion, make magnetic skyrmions fundamentally promising for applications in next-generation high-density and low-dissipation memory devices. [1-5]