We study the boundedness problem for maximal operators Mσ associated to flat plane curves with Mitigating factors, defined by Mσf(x):=1≤t≤2sup∫01f(x−tΓ(s))(κ(s))σds, where κ(s) denotes the curvature of the curve Γ(s)=(s,g(s)+1),g(s)∈C5[0,1] in R2. Let △ be the closed triangle with vertices P=(52,51),Q=(21,21),R=(0,0). In this paper, we prove that for (p1,q1)∈[(p1,q1):(p1,q1)∈△∖{P,Q}]∩[(p1,q1):q>max{σ−1,2}], there is a constant B such that ∥Mf∥Lq(R2)≤B∥f∥Lp(R2).