In this study, a biological permeable reactive barrier system was designed to evaluate the remediation effectiveness of BTEX-contaminated groundwater. The biological barrier using immobilized bio-beads encapsulated with calcium alginate and activated carbon fiber as microbial carrier is able to biodegrade BTEX entering the barrier system. A laboratory-scale experiment using one continuous up-flow stainless steel column was then performed to evaluate the feasibility of this designed system. The second column was filled with bio-beads immobilizing BTEX-degrading microbial consortium. Simulated BTEX-contaminated groundwater, in which dissolved oxygen (DO) content was saturated, was pumped into this system at a flow rate of 0.07ml/min. Samples from the column were analyzed for BTEX and effluent DO. Results showed that BTEX could be well removed in this biological barrier.