The high bit rate of data is transmitted for longer distances by using Dense wavelength division multiplexing. Dense wavelength division multiplexing is mainly affected by the Stimulated Raman scattering effect of optical nonlinearity. This effect transfer energy from a lower wavelength to a higher wavelengt h as the result the Quality factor decreases and BER increases. This thesis analyzes the performance and characteristics of SRS in the DWDM fiber communication system at 10x10Gbps using the combined effect of a Hybrid amplifier namely Raman + SOA and Raman + EDFA that connected in parallel with the modulated scheme of RZ, NRZ, and Duobineary at its maximum transmission distance. SRS effect is studied for various power levels of each combination (hybrid amplifier and modulation scheme) by simulating using Opt i system software tools. Raman + EDFA and Raman + SOA transmit the signal up to 130Km however, Raman + EDFA with RZ and Duobinary modulator have minimum BER and high-quality factor than Raman + SOA for the input power of less than or equal to 14 and 12 dBm respectively . Key Words: BER, DWDM, Quality factor, Signal dispersion, SRS