In this book was presented a full simulation of the Barrel Calorimeter of the KLOE detector with FLUKA Monte Carlo package. This implementation of the geometry was used for simulations of the physical energy response of the calorimeter. Also was estimated influence of merging and splitting of clusters for reconstruction possibilities of the particles on the whole Barrel Calorimeter with a present clustering algorithm. In particular these effects were estimated as a function of the quantum efficiency of photomultipliers. The prepared program with geometry of the 24 modules of the barrel calorimeter enables fast simulations of a choosen reaction channel and facilitates studies of the detector response to different reactions separately. Additionally the influence of merging and splitting of clusters on reactions with high number of photons in the final state was estimated.