In this paper, we investigate uniqueness problems of differential polynomials of meromorphic functions. Let a, b be non-zero constants and let n, k be positive integers satisfying n ≥ 3k + 12. If fn+ af(k)and gn+ ag(k)share b CM and the b-points of fn+ af(k)are not the zeros of f and g, then f and g are either equal or closely related.
