Аннотация:MASTER-SAAO robotic telescope (Global MASTER-Net: http://observ.pereplet.ru, Lipunov et al., 2010, Advances in Astronomy, vol. 2010, 30L) located in South Africa (South African Astronomical Observatory) was pointed to the Swift GRB 210308A ( V. D’Elia et al., GCN 29619) errorbox 40899 sec after notice time and 40918 sec after trigger time at 2021-03-08 17:59:54 UT, with upper limit up to 13.9 mag. Observations started at twilight. The observations began at zenith distance = 74 deg. The sun altitude is -12.2 deg. MASTER-IAC robotic telescope located in Spain (IAC Teide Observatory) was pointed to the Swift GRB 210308A errorbox 55958 sec after notice time and 55976 sec after trigger time at 2021-03-08 22:10:53 UT, with upper limit up to 18.5 mag. The observations began at zenith distance = 48 deg. The sun altitude is -40.8 deg. The galactic latitude b = -7 deg., longitude l = 164 deg. Real time updated cover map and OT discovered available here: https://master.sai.msu.ru/site/master2/observ.php?id=1563625 We obtain a following upper limits. Tmid-T0 | Site |Filt.| Expt. | Limit| Comment _________|_______________ ______|_____|_______|______|______ __ 21950 | MASTER- | C | 60 | 18.0 | 22210 | MASTER- | C | 60 | 15.8 | 22945 | MASTER- | C | 60 | 12.6 | 41008 | MASTER-SAAO | C | 180 | 13.9 | 56067 | MASTER-IAC | C | 180 | 18.5 | Filter C is a clear (unfiltred) band. The observation and reduction will continue. The message may be cited.