Most of the one dimensional spin chain compounds are antiferromagnetic with a rich magnetic phase diagram due to the magnetic frustration. We have synthesized Ba3CrS5 and Ba3CrSe5, which forming chains of CrS(Se)6 octahedra along c-axis. The magnetic structure, investigated using neutron diffraction study reveals the ferromagnetic arrangement of the Cr3+ moments in the ab-plane, while anti-ferromagnetic coupling of the FM planes along the c-axis. Based on the DFT+U calculation, we have found the band gap is ~0.78 eV. Our recent INS study on Ba3CrS5 shows the signature of short range ordering. Hence, detailed study regarding nature of magnetic ground state of these spin chain compounds, Ba3CrS5 and Ba3CrSe5 is important to get insight of physics behind the various interesting properties of these systems and for this investigation muon spin relaxation is a very useful tool.