Abstract: In this paper, using the method of the maximum entropy spectrum estimation, three kinds of data are analysed. They include phase and amplitude of LFand VLFobserved in the Eastern hemisphere (20°S-65°N, 13°E-141°E), Ly-α radiation flux measured by satellite, and the planetary wave in the high latitude during three winters from 1985 to 1988. These results show that(1) The phase disturbances at LFand VLFhave periods with 2-2.2, 3-4, 6-12, 12-20 and 20-32 days, while the solar I.y-α radiation flux presents 20-30 days fluctuation as well.(2) In the winter, larger amplitude distubmces at LFhave fairly good correlation to the planetary wave H₁ observed in the high latitude (60°N), valleys and peaks of their wave forms correspond each other except shifting about 3-4 days in the time axis. Cross correlation coefficients are between 0.65 and 0.85, We also notice that there are little differences between them.The observed results are compared with those of the spectral analyses, and considered that Ly-a radiation flux variation could be a reason which causes disturbances of LFand VLFwith period more than 20 days, while those with periods ranging from 2 to 20 days seem to be controled by the planetary waves from the stratosphere and troposphere.