In this paper, we study orbital stability of peakons for the generalized modified Camassa-Holm (gmCH) equation, which is a natural higher-order generalization of the modified Camassa-Holm (mCH) equation, and admits Hamiltonian form and single peakons. We first show that the single peakon is the usual weak solution of the PDEs. Some sign invariant properties and conserved densities are presented. Next, by constructing the corresponding auxiliary function h(t, x) and establishing a delicate polynomial inequality relating to the two conserved densities with the maximal value of approximate solutions, the orbital stability of single peakon of the gmCH equation is verified. We introduce a new approach to prove the key inequality, which is different from that used for the mCH equation. This extends the result on the stability of peakons for the mCH equation (Comm. Math. Phys., 322:967-997, 2013) successfully to the higher-order case, and is helpful to understand how higher-order nonlinearities affect the dispersion dynamics.Recently, the great interest in the CH equation has inspired the search for various CH-type equations with cubic or higher-order nonlinearities. One of the most concerned is the following modified CH (mCH) equationwas derived by Fuchssteiner [22] and Olver and Rosenau [32] by employing the tri-Hamiltonian duality approach to the bi-Hamiltonian representation of the modified KdV equation. Subsequently, the integrability and structure of solutions to the mCH equation was discussed by Qiao [33]. The mCH equation is also called FORQ equation in some literature [26, 41]. The mCH equation is completely integrable [32]. It has a bi-Hamiltonian structure and also admits a Lax pair [35], and hence may be solved by the inverse scattering transform method. Compared with the CH equation, the mCH equation admits not only peakons, but also possesses cusp solitons (cuspons) and weak kink solutions (u, u x , u t are continuous, but u xx has a jump at its peak point) [35,40]. It has also significant differences from the CH equation on the dynamics of the multi-peakons and peakon-kink solutions [24,34,40]. Fu et al.,[21] studied the Cauchy problem of the mCH equation in Besov spaces and the blow-up scenario. The nonuniform dependence on the initial data was established in [26]. Gui et al.,[24] considered the formulation of singularities of solutions and showed that some solutions with certain initial data would blow up in finite time. Then the blow-up phenomena were systematically investigated in [7,31]. The mCH equation admits single peakon of the form [24] u(t, x) = ϕ c (x − c t) = 3 c 2 e −|x−c t| , c > 0. Later, inspired by [16] and [18], the orbital stability of single peakon and the train of peakons for the mCH equation were proved in [36] and [30], respectively.