LetG be a group. Let R be a G -graded commutative ring with identity, and let M be a G -graded module over R. Two graded submodulesN and K of graded module M are called graded coprime whenever N+K=M. In this paper, some properties of graded coprime submodules are discussed. For example, we show that ifM is a graded finitely generated module, then two graded submodulesN and K of M are graded coprime if and only if gradM (N) and gradM (K)are graded coprime.