TG-MS simultaneous measurement on a nominally chromium deficient lanthanum calcium chromite, (La0.7Ca0.32)CrO3, has been made in a helium flow and the results were compared with its shrinkage behavior in air and also with TG-DTA results on related calcium chromium oxides (n(CaO)/n(CrOx) = 1:1 and 5:3) in air. In addition to evolution of water (320-920 K and 1020-1120 K) and carbon dioxide (340-1120 K), four distinct oxygen evolution peaks were observed from 900 to 1600 K; this oxygen evolution can be ascribed to the successive reduction of chromium ions in second phases which were estimated as about 1 mol% of Ca-5 (CrO4)(3) or 2 mol% of Ca-3(CTO4)(2). With the aid of available phase diagrams, a peak of simultaneous water and oxygen evolution at 1020-1120 K was attributed to the decomposition of an intermediate reaction compound, Ca-5(CTO4)(3)OH. Similarly, the water evolution at 320-920 K and CO2 evolution can be ascribed to the decomposition of hydrated calcium chromates, CaCrO4 . nH(2)O and calcium carbonate which were considered to be formed as reaction products of Ca-5(CrO4)(3) with water, oxygen, and carbon dioxide. These features were discussed in relation to the sintering behavior of chromium deficient lanthanum calcium chromite.