We present one of the results of BVRI photometry of the hosts of GRB for the host galaxy of GRB 970508 and the theoretical modeling of its continuum spectral energy distribution ( SED ) to show that it is important to take into account internal extinction in the host galaxies .
We compared the BVRI broad-band flux spectrum of the host to template SEDs of local starburst galaxies and found that there is a significant internal extintion in this host .
Moreover , this comparison allows us to derive the absolute magnitude ( M _ { B _ { rest } } ) and rouhgly estimate reddening ( A _ { V } ) .
Population synthesis modeling of the continuum SED for different reddening laws ( ( ( 4 ) ) and ( ( 5 ) ) ) demostrates that the observational data of the host galaxy of GRB 970508 are best fitted by the spectral properties of a model SED with extinction of A _ { V } \approx 2 .