Implementing complex bioanalytical assays on fully integrated and scalable labon-a-chip(LOC)devices has great potential in key biomedical applications such as point-of-care(POC)application.Comparing to the active microfluidic systems driven by external power sources,capillary-driven microfluidic devices have received increasing interests as they drive the liquid sample by the intrinsic capillary forces without the requirements of any active components,such as pumps or valves,thus especially suitable for the POC applications.In this presentation,novel Silicon-based capillary microfluidic devices that possess multiple functionalities,such as capillary pump,passive valve and switcher were fabricated using Silicon micro-fabrication technology.With these autonomous devices,successful on-chip PCR and DNA detection were demonstrated with very low sample and time consumption.