1 Catholic University of America, Department of Physics, Washington D. C. 20064

2 NASA/GSFC, Greenbelt, MD 20771

3 NAS/NRC Senior Research Associate

We present a study of the time evolution of radio spectral index in the frequency range from 50 MHz to 17 GHz for a set of solar eruptive events involving coronal mass ejections and energetic particle events. We include spatial information of the flares from Yohkoh/HXT images in determining the spectral evolution. We also study the timing of long wavelength radio bursts observed by Wind/WAVES experiment to determine all possible sources of energetic particles. We compare and discuss the relationship between the hard X-ray, radio and energetic particle spectra in order to understand the acceleration process during these eruptive events.