Showdomycin is a naturally maleimide antitumor antibiotic of the C-nucleoside, it inhibits the nucleic acid synthesis in bacteria. Conformational analysis and geometry optimization of showdomycin was performed according to the Hartree-Fock (HF) calculation method by ArgusLab 4.0.1 software. The minimum potential energy is calculated by geometry convergence function by ArgusLab software. The most feasible position for the drug to interact with the receptor was found to be 0.269696 K.cal/mole.