A Vertical Flow Immunoassay (VFA) comprises of stacked nitrocellulose membrane and absorbent pads to create a system for sample vertically passing through, featured as rapid, high multiplex capability, high sensitivity and larger volume capacity. We have developed a rapid VFA to detect IL-6, within 15 min, with a wide reportable range 10-10,000 pg/ml that can be used as supporting information for the inflammation activity of rheumatic arthritis, COVID-19 induced cytokine release syndrome (CRS), CAR-T therapy induced CRS and sepsis. The significance of this work is to provide real time monitor on their IL-6 level for cost-saving and lifesaving, rather beneficial for human health, the medical system, and the economy.