We give coefficient estimates for a class of close-to-convex harmonic mappings F , and discuss the Fekete-Szegő problem of it. We also determine a disk |z| < r in which the partial sum s m,n ( f ) is close-to-convex for each f ∈ F . Then, we introduce two classes of polyharmonic mappings HS p and HC p , consider the starlikeness and convexity of them and obtain coefficient estimates for them. Finally, we give a necessary condition for a mapping F to be in the class HC p .