To evaluate regional differences of global ultraviolet-B (UVB: 290-315 nm) irradiance, eight band-spectral UVB radiometers (MS-210W, EKO), which were used in the UV monitoring network organized by five universities, were compared at the Shonan Campus of Tokai University, Japan from August 2-10, 1997. Reference irradiances were measured by a spectroradiometer (OL752, Optronic Lab.) and the reference band-spectral UVB radiometer (MS-210W, EKO). UVB radiometers participated were classified into three groups by the characteristics of the spectral response depending on the UVB irradiance. It suggests that characteristics of out of band is different from the reference radiometer. Furthermore, to access regional difference of UVB, it is necessary to use the calibration factor that is not constant but a function depending on output.