  Here, we study the generalized second law (GSL) of thermodynamics in the
framework of massive gravity. To do this, we consider a FRW universe filled
only with matter and enclosed by the apparent horizon. In addition, we consider
two models including generalized massive gravity (GMG) as well as dRGT massive
gravity on de Sitter. For both models, we first study the dynamics of
background cosmology and then explore the validity of GSL. We conclude that for
the selected values of model parameters the GSL is respected.
