We generalize Catoni's M-estimator, put forward in [3] by Catoni under finite variance assumption, to the case in which distributions can have finite α-th moment with α ∈ (1, 2). Our approach, inspired by the Taylor-like expansion developed in [4], is via slightly modifying the influence function ϕ in [3]. A deviation bound is established for this generalized estimator, and coincides with that in [3] as α ↑ 2. Experiment shows that our M-estimator performs better than the empirical mean, the smaller the α is, the better the performance will be. As an application, we study an 1 regression considered by Zhang et al. [19], who assumed that samples have finite variance, under finite α-th moment assumption with α ∈ (1, 2).