Abstract. In this paper, we investigate linear Weingarten hypersurfaces with two distinct principal curvatures in a real space form M n+1 (c), we obtain two rigidity results and give some characterization of the Riemannian product2010 Mathematics Subject Classification. 53C42, 53A10.1. Introduction. Let M n be an n-dimensional hypersurface in a real space form M n+1 (c) of dimension n + 1. It is well known that there are many rigidity results for hypersurfaces in a real space form with constant mean curvature or with constant scalar curvature or with the scalar curvature and the mean curvature being linearly related. For example, one can see [2-6, 8-11].Recently, H. Li, Y. J. Suh and G. Wei [7] introduced the so called linear Weingarten hypersurface in a unit sphere S n+1 (1). We can generalize it to a real space form M n+1 (c), that is, a hypersurface in a real space form M n+1 (c) is called a linear Weingarten hypersurface if the scalar curvature R and the mean curvature H satisfy the linear relation αR + βH + γ = 0, where α, β and γ are constants such that α 2 + β 2 = 0. We easily see that if the constant α = 0, a linear Weingarten hypersurface reduces to a hypersurface with constant mean curvature. If the constant β = 0, a linear Weingarten hypersurface reduces to a hypersurface with constant scalar curvature. If the constant γ = 0, a linear Weingarten hypersurface reduces to a hypersurface with the scalar curvature and the mean curvature being linearly related, which was studied by H. Li [6] for the unit sphere. Therefore, we know that the linear Weingarten hypersurface is a natural generalization of hypersurface with constant mean curvature or with constant scalar curvature or the scalar curvature and the mean curvature being linearly related.In this paper, we try to study the linear Weingarten hypersurfaces with two distinct principal curvatures in a real space form M n+1 (c). In order to state our theorem clearly, we introduce the well-known standard models of complete hypersurfaces inThen N k,n−k has two distinct constant principal curvatures 0 and √ a with multiplicities k and n − k, respectively. Let M k,n−k := S k (a) × S n−k ( √ 1 − a 2 ). Then M k,n−k has two distinct constant principal curvatures