This paper presents the comparison between two different geometries for the core of homo polar linear synchronous motor HLSM. The theoretical analysis estimated the airgap flux density , the attraction and traction forces This analysis is based on a magnetic field study using 3-dimensional finite difference method FDM of scalar magnetic potential. The average results of zero and infinite permeability boundaries is considered. The flux per pole, under a.c. limbs either in"C" or in " XI" core is taken for obtaining the majority of normal force. Results reveal that the " XI" core shape was the optimum form because it provides higher both of traction and attraction forces than "C" core . But, the extra iron required and attraction force s than "C" core. But, the extra Iron required and the cost of rail track poles were the weak points for unchoosing this form in practical application An experimental investigation is carried out on laboratory Static prototype motor LSPM of "C" core HLSM to verify the theoretical results. It is shown that the experimental and computed results are in good agreement.