As to traditional active control of structural responses (ACSR) for helicopter in frequency-domain, the control output is obtained according to determ inistic optimal principle, the computation cost of which is large. The output is sensitive to external disturbances especially at the beginning of control. Aiming at the targets that effectively restrain divergence and smooth control output, two new modified methods are proposed based on a traditional technique. One is dual normal least mean square (NLMS) method in which frequency response matrix of con trol path and the amplitude of external excitation response are identified. The other is L&K method that the needed variables are identified by Kalman filtering after primary identification of LMS method. Simulation results show the effectiv eness of these two methods .