In the present paper, the authors introduce two new subclasses Ss( k ) ( φ{symbol} ) of close-to-convex functions and Cs( k ) ( φ{symbol} ) of quasi-convex functions. The integral representations for functions belonging to these classes are provided, the convolution conditions, growth theorems, distortion theorems and covering theorems for these classes are also provided. The results obtained generalize some known results, and some other new resu...