Abstract: By using FFT,this paper carries out the spectrum analysis of the transformation parameter results from the International GLONASS Experiment(IGEX) BKG Analysis Center.We found that the three rotation parameters all have primary periods 293.7 days,685.3 days and 1 028.0 days with the amplitude being about 9.1~16.3mas.On the other hand,the remaining parameters also have the same long period fluctuations,but they aren't the dominant.The scale,translations T_x and T_y show more stable,their constant and bias terms could be neglected compared to the large rms.The fluctuation of translation T_z is similar to the rotations,and the bias term is evident,its first primary period is 293.7days.A set of transformation parameters based on our investigation are suggested.