The project concern with using of Quantum mechanics Calculation methods PM3 and AM1 methods by using the program Hyper chem. 8.08 to calculate the equilibrium geometrical structure of the drugs. Carbamazepine and its derivatives (R = -OH, -OCH3, -F2, -OCOCH2CL, -Br) which are yet unused as a drugs. The physical properties of the drug and it' s derivatives were calculate at their equilibrium geometrical structure as bond length, heat capacity, enthalpy, total energy, dipole moment, EHOMO, ELUMO, ionization energy, electron affinity and the IR, UV- Vis spectra. The theoretical results showed that energy of the derivatives (F2, Br) was similar to that of the drug and both have ionization energy similar to that of the drug, this result was improved by the similar polarity of both drug and derivatives