TITLE: GCN CIRCULAR NUMBER: 31159 SUBJECT: GRB 211201A: GECAM detection DATE: 21/12/03 01:04:55 GMT FROM: Guoying Zhao at IHEP G. Y. Zhao, S. L. Xiong,X. L. Zhang, S. Xiao, Yi Zhao, C. Cai, J. J. He, Y. Huang, Z. W. Guo, C. Y. Li, X. B. Li, J. C. Liu, X. Y. Song, P. Wang, S. L. Xie, W. C. Xue, Q. B. Yi, Y. Q. Zhang, X. Y. Zhao, C. Zheng, Y. Q. Du, D. Y. Guo, J. Liang, F. J. Lu, Q. Luo, X. Ma, W. X. Peng, R. Qiao, L. M. Song, J. Wang, H. Wu, P. Zhang, S. N. Zhang, C. W. Wang,Z. Zhang, S. J. Zheng (IHEP),report on behalf of GECAM team: During the commissioning phase, GECAM-B was triggered on-ground by a long bright burst, GRB 211201A, at 2021-12-01T20:43:06.000 UTC (denoted as T0)��� which was also observed by Fermi/GBM (GCN #31155). This burst mainly consists of multiple pulses with duration of about 50 s. The GECAM light curve could be found here: http://twiki.ihep.ac.cn/pub/GECAM/GRBList/LightCurve.png GECAM location is consistent with the Fermi/GBM position within the error. Please note that all GECAM results here are preliminary. The final analysis will be published in journal papers or GECAM online catalog. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in Low Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time), which was funded by the Chinese Academy of Sciences (CAS).