A system for analyzing/inspecting airborne radioactive particles sampled in a draft flue is disclosed, which comprises: a front detector, at least an air intake tube, a capture vessel, an inspection device, a flow meter, a hand-held electric device, a blower motor, With the aforesaid system, the radioactivity distribution relating to the airborne particles as well as the peak of the distribution can be detected, by which a sampling time can be determined for achieving longer period of time allowed for an analysis to be performed while rejecting the radioactive interference in the draft flue. Thereby, background noise relating to ambient radioactivity can be minimized and thus the detection limit of the aforesaid system is reduced, so that the system of the invention is much more sensitive compared to those conventional real-time radioactivity detection means with regard to the detection of radioactive nuclides in airborne particles.