The next generation passive optical network is a network that provide high bitrate data transmission in ITU-T standard. Currently there is high need of speed in broad band service in order to utilize triple-play (voice, data, video) which is the driving force of new access technology because bandwidth utilization and XG-PON is one of a solution for this application but it need to consider Fiber attenuation, splice losses, signal dispersion non linearity and back-reflections as in realistic fiber plant been considered for this XG -PON system as it mainly affects link performance. This papers try to analyses the above effects for XG-PON transmission link performance using Erbium doped fiber amplifier(EDFA) characteristics and dispersion compensation fiber(DCF) technology , Optisystem simulator is a tool in evaluation of the signal performance. The research analyses the performance of Downstream XG-PON(10Gbps) link with and without EDFA and DCF for the effect of dispersion and attenuation by considering acceptable bit rate between 10-120km the EDFA is used with the pump wavelength of 980nm and simulated in order to obtain higher gain and lower noise at 1550nm wavelength and 0.2dB attenuation is considered for the design during simulation. As fiber length increase the signal distortion increase and quality decrease without EDFA and DCF by considering BER and Q-Factor so it need both technologies in order to have better transmission link performance and quality of service at the user end. KEY WORDS: CD, DCF, EDFA, NRZ, OLT , ONU, PMD, RZ, XG-PON.