Quite recently, Ouyang-Zhang proposed an interesting approach to construct uninorms via closure (interior) operators on a bounded lattice. In which, they defined an important closure (interior) operator by the notion of universally comparable element when the bounded lattice is complete. However, their operators are not well defined in general when the bounded lattice is not complete. In this paper, we define a closure (interior) operator on bounded lattice, and prove that these operators reduce into Ouyang-Zhang’s operators when the bounded lattice is complete. Hence our closure (interior) operator can be regarded as the extension of Ouyang-Zhang’s closure (interior) operator to noncomplete bounded lattice. At last, the uninorms corresponding to the closure (resp., interior) operator are constructed and discussed