In this paper, we shall study the uniqueness problems of differential polynomials of meromorphic functions sharing 1 value. Here we prove two uniqueness theorems which extend and improve recent results of H.P. Waghamore and N.H. Sannappala [10]. 1 corresponding author 2010 Mathematics Subject Classification. 30D35. 119 120 N. MANDAL AND A. SHAWm ≤ l and l + 1 times if m > l. If E l (a, f ) = E l (a, g), then we say that f and g share the value a with weight l. We also use the notation N (r, a; f |p) to denote the counting function of f − a where m fold zeros is counted m times if m ≤ p and p times if m > p , where p is an integer. Definition 1.1. [4] Let f is a nonconstant meromorphic function and a ∈ C ∪ {∞}, the counting function of a-points of f with multiplicities at least p(∈ Z + ) is denoted by N (r, a; f |≥ p) and N (r, a; f |≥ p) is the corresponding reduced counting function. Similarly we can define N (r, a; f |≤ p) and N (r, a; f |≤ p). Definition 1.2. [4] The counting function of a-points of f , where an a-point of multiplicities m is counted m times if m ≤ p and p times if m > p is denoted by N p (r, a; f ), where p ∈ Z + ∪ {∞}. Then we can write: