The emission of charged particles in 4.5 GeV/c proton-Emulsion interactions has been studied. The emulsion plates have been irradiated at Dubna Synchrophasatron.The experimental data were obtained at the Laboratory of High Energy Physics (LHEP)at Cairo University. Events have been chosen from the experimental data at certen conditions. In the present studies the average transverse momentum projected onto the reaction plane PT and the emission angle have been investigated . The trasnsverse momentum techniqe has been used to chek the sideward flow of charged particles in the considered reactions. The reaction plane have been determined in each evevnts and the transverse momentum (the momentrum component in the azimuthal plane) was projected onto the reaction plane. The dependence of PT on the pseudorapidity  has been studied. The study has shown a significant sideward flow of thge charged particles in the region of large pseudoraidity(i.e.small values of space angle). The sideward flow of nuclear matter semes to be as aresults of the interaction between any two composite particles. Back-Back emission has been observed for the produced shower particles and the emitted target fragments. From this study one can coclude that the determination of the reaction plane is a powerful tool for the investigation of the sideword flow of nuclear matter.