In this paper, we establish some left and right multiplicative perturbation theorems concerning local C-semigroups when the generator A of a perturbed local C-semigroup S(⋅) may not be densely defined and the perturbation operator B is a bounded linear operator from D(A)¯\documentclass[12pt]{minimal}
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\begin{document}$\overline {D(A)}$\end{document} into R(C) such that CB=BC on D(A)¯\documentclass[12pt]{minimal}
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\begin{document}$\overline {D(A)}$\end{document}, which can be applied to obtain some additive perturbation theorems for local C-semigroups in which B is a bounded linear operator from [D(A)] into R(C) such that CB=BC on D(A)¯\documentclass[12pt]{minimal}
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\begin{document}$\overline {D(A)}$\end{document}. We also show that the perturbations of a (local) C-semigroup S(⋅) are exponentially bounded (resp., norm continuous, locally Lipschitz continuous, or exponentially Lipschitz continuous) if S(⋅) is.