The relationship amang radioluminography (BAS-2000), two-dimentional position sensitive multiwire proportional counter (AMBIS-4000) and autoradiography using X-ray film were examined for their efficiencies for14C-labelled compounds. Detection efficiencies of BAS-2000 and AMBIS4000 were 0.093% and 1.35%, respectively. There was a good relationship between the two methods. On the other hand, the autoradiography was not sensitive enough to detect labelled materials of 0.018 kBq. However, distances between two shadow spaces of the labelled materials were 3.35 mm by autoradiography, 2.61 mm by BAS-2000 and 1.62 mm by AMBIS-4000.