The College of Science in the Department of Mathematics discussed a master thesis titled study of stability and instability thresholds for the problem of thermal and salt convection of Kelvin-Voigt fluid for postgraduate student Duaa Zuhair. the thesis aims to produce a numerical solutions that are obtained by using the golden- section techniques in the Matlab platform. The effects of Kelvin-Voigt parameters and viscoelastic parameters on the stability of the system are investigated.