The noise characteristics of LD-pumped Nd∶YVO4/ KTP ( Ⅱ-typed) green lasers were observed in this paper. It shows the noise has arisen from the coupling of different longitude modes in the frequency doubler —KTP. At last , two effective methods to eliminate green noise , including inserting a Brewster plate in the resonator of a Nd∶ YVO4/ KTP laser , and using type- Ⅰ phase matching BBO as the frequency doubler , were introduced , respectively.