We have studied the Uracil system with a set of 4,12b-Dihydro-3-thioxo-1H,7H-chromeno [4/,3/:4,5]pyrano[2,3- d]pyrimidine-1(2H)-one of different electronic features using several methods. Calculations based on density functional theory(DFT)have been performed to investigate the stabilities. Our aim is to find the lowest energy uracil derivatives in different solvents. Also recognize the stability of different functional groups in the biological molecules is important. The investigated models have been relaxed to minimum energy structures. The combined IR , NBO and physical properties of the molecule have been evaluated. The solution changes caused that significant amount is changed Energy and properties of these molecules. Different functional groups can have various effects on Stability of the molecule and cell receptor. So by replacing the different functional groups, The calculations were carried out and optimal energy Was obtained.