A reflection-based tubular waveguide particle plasmon resonance sensing system and a sensing device thereof are provided. The sensing device includes a hollow tubular waveguide element having wall, a reflection layer disposed on one end of the wall (distal end), and a noble metal nanoparticle layer distributed on the surface of the wall. An incident light enters the wall through another end of the tubular waveguide element (proximal end) and being total internal reflected many times along the wall, then is reflected by the reflection layer and being total internal reflected many times along the wall again, and finally, the incident light exits the proximal end. Wherein, when the sample contacts the noble metal nanoparticle layer of the tubular waveguide element, the particle plasmon resonance condition is altered and hence the signal intensity of the light exiting the tubular waveguide element changes.