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In this paper,we provide a bijection between the set of underdiagonal lattice paths of length n and the set of(2,2)-Motzkin paths of length n.Besides,we generalize the bijection of Shapiro and Wang(Shapiro L W,Wang C J.A bijection between 3-Motzkin paths and Schr?der paths with no peak at odd height.J.Integer Seq.,2009,12:Article 09.3.2.)to a bijection between k-Motzkin paths and(k-2)-Schr?der paths with no horizontal step at even height.It is interesting that the second bijection is a generalization of the well-known bijection between Dyck paths and 2-Motzkin paths.