The purpose of this research is to generate the detailed geometry of the inner barrels of the inner tracking system (ITS) upgrade at ALICE, CERN. The new ITS are divided into two parts, inner and outer barrels. Each part consists of detector barrels and service barrels. The scope of our work is limited to detector barrels and DC to DC power supply of the inner barrels, using AliROOT framework. The geometry is written in C++ programming language and compiled to “.root” files. These files can be used in the simulation process of the experiments and in the calculation of material budgets.