The recent finding [12] that spin-orbit coupling can have a major effect on the electronic structures calls for a detailed investigation of the role of SOC in 4d oxides. In the proposed work, we plan to investigate the magnetization distribution in Ca2RuO4 single crystals by polarized neutron diffraction measurements. We would like to compare the experimentally observed spin density maps with simulated ones for the S = 1 case (crystal field dominates) and J = 0 case (SOC dominates) to understand the effect of SOC on the ground state electronic configuration. The outcome of the proposed experiment will help in determining the radial part of the Ru magnetic form factor and possibly to establish the symmetry of Ru 4d orbitals in Ca2RuO4.