Amino acids of solid state DL-beta-amino-n-butyric acid (BABA), Triethylene tetramine hexa acetic acid (TTHAA) and DL-Asparagine monohydrate (DLAMH) have been investigated by Electron Paramagnetic Resonance Spectroscopy. Free radicals formed in irradiated powder crystals have been examined at temperatures of 300 Kelvin. The structure of the free radical and the hyperfine structure constants were reported. The free radicals formed in the compounds were found to be stable for three months, fifteen days and two months respectively. The obtained results are in agreement with the literature values.