Design and optimizing the drilling and blasting parameters, should fill the requirements for the capacity, fragmentation size, and technical characteristics of loading and transport equipment, and enable a safe work at the open pit. Besides mentioned, it also achieves the minimal impact on the environment of the open pit and decreases the negative effects on the environment, especially in the blast vibration and flyrock. To obtain the best possible blasting effects and consider all the factors, a specialized software is used to optimize the drilling and blasting parameters. Currently, the few software is intended for optimizing the drilling and blasting works. This paper presents calculation in the OPitblast software, where the estimation of drilling and blasting parameters was performed. As the software has different possibilities for interpretation the results, the prediction of the fragment size distribution of the blasted material, based on the analysis of designed parameters at the open pit copper mine, is presented. The software provides the optimization of drilling and blasting parameters with a very simple change of the set parameters, regarding those, related to the rock mass properties, the characteristics of explosives during blasting, initiation system, delay time to output values such as the size of the blasted material, determination the safety zone of flyrock or negative blast vibration effects.