The Fe 3 O 4 /ZnO/MWCNTs magnetic nanocomposites as a high-performance organomettalic catalyst were employed for the preparation of new chromeno pyrano [2,3-d]thiazins derivatives in high yields via the five component reactions of 2-hydroxyacetophenone or its derivatives, dimethyl carbonate, aldehydes, malononitrile or ethyl 2-cyanoacetate, and isothiocyanates in ionic liquid at room temperature. The Fe 3 O 4 /ZnO/MWCNTs MNCs were synthesized using ionic liquid [OMIM]Br as a stabilizer and soft template. As well Fe 3 O 4 /ZnO/MWCNTs MNCs show a good improvement in the yield of the product and showed significant reusable ability. Due to having NH group in synthesized compounds, we investigate antioxidant property of some synthesized compounds by diphenyl-picrylhydrazine (DPPH) radical trapping and power of ferric reduction experiment. Furthermore, the disk diffusion test on Gram-positive and Gram-negative bacteria is utilized for investigation of antimicrobial activity of some chromeno pyrano [2,3-d]thiazins. The achieved outcomes of this experiment demonstrate that these synthesized compounds could prevent from growth of bacteria. Short time of reaction, high yields of product, easy separation of catalyst, and products are some benefits of this process. K E Y W O R D S (DPPH) radical, chromeno pyrano [2,3-d]thiazins derivatives, Fe 3 O 4 /ZnO/MWCNTs MNCs, five component reactions