  We consider the imbalance of matter and antimatter by using a gravitational
baryogenesis mechanism in the background of Dvali-Gabadadze-Porrati (DGP) brane
cosmology. By taking into account a flat Friedmann-Lemaitre-Robertson-Walker
(FLRW) metric in the DGP brane model, we find that for a radiation dominated
universe, $w = 1/3$, the ratio of baryon number density to entropy from the
gravitational baryogenesis is not zero, contrary to ordinary general
relativity. Also, we study the ratio of baryon number density to entropy
against the observational constraints in DGP cosmology.
