Automated　chip-based　technologies　for　clinical　diagnosis　may　have　great　facilities　in　the　area　of　life　science　and　medicine.　This　paper　presents　the　lab-on-a-chip　design　for　the　assay　of　HIV,　which　includes　the　sample　preparation,　reaction,　and　signal　amplification　module.　A　laser　induced　fluorescence　system　is　also　designed　for　real-time　monitor　of　the　signals.