A Master thesis titled (Density of States and Tunnelling Magnetoresistance Calculation for Double Quantum Dots Connected in Parallel Shape to Ferromagnetic Leads) was defended at College of Science, Department of physics on )21 Sep 2023), for the postgraduate Candidate  Laith Nazar Ramadhan. The aim of the thesis is to find a mathematical model and formulate it theoretically to determine the transport properties in a symmetric system consisting of Double quantum dots connected to ferromagnetic Leads.