Eggplant Solanum melongena is an economically important crop with a wide range of shapes and colors of fruit. To evaluate the effect autotetraploidy, eggplant seeds of "Keshtzar", "Chahboland" and "Yalda", and "Pasargad Ps077B" hybrid variety of sweet eggplant were collected and treated by 0, 0.1, 0.5 and 1% colchicine with seed soaking and shoot tip maceration methods. Flow cytometry and chromosomal counting used to determine ploidy level. The efficiency and percentage of normal polyploid were calculated to determine the best induction treatment. To compare the characteristics of plants with different ploidy levels, seedlings of each produced polyploid forms planted into the field at 75 × 30 × 40 intervals. Then, changes in plant architecture like leaf, stem, flower, and fruit compared between different forms.