A reactor-based facility of neutron capture, prompt gamma-ray spectrometry for activation analysis has been installed at the 1-MW low-power Tsing-Hua Open Pool Reactor. The system consists of a neutron beam port with collimators, irradiation station, external beam tube, neutron beam catcher, and counting system. The counting system contains a 25% n-type high-purity germanium, main gamma-ray detector, a 9- × 10-in. Nal(Tl) detector shield, and Compton-suppression/pair spectroscopic electronics coupled to the Canberra S-88 multiparameter analyzer. Although the neutron beam at the sample irradiation station has an intensity of only 1 300 000 n/cm2.s with a cadmium ratio of 26 to 1, the background levels of the on-line measurement in the mixed neutron/gamma field are sufficiently low, resulting in satisfactory detection of many elemental compositions in samples. The lower limits of detection of 42 elements in a sample matrix of the present system, its applications, and planned upgrade are considered.