Abstract: The pathways of pyruvate oxidation in subc'ellular particles (mitochondria) prepared from shoots of 4-day old etiolated rice seedlings were studied. The operation of the tricarboxylic acid (TCA) pathway was established by the following results: 1. Succinate and α-ketoglutarate were oxidised rapidly by the panicles followed by citrate, malate and fumarate in decreasing order of rapidity. 2. Pyruvate oxidation was accelerated by catalytic amount of succinate. The operation of condensing enzyme is thus indicated. 3. Succinate oxidation was inhibited by malonate, α-Ketoglutarate oxidation was inhibited by arsenite. The latter inhibition was reversed by addition of succinate. 4. When reaction mixtures were examined for products on paper chromatograms, succinate was found to be converted to fumarate, malate and isocitrate, α-ketoglutarate was found to be converted to succinate, fumarate and malate. The presence of glyoxylate pathway along with the TCA route of pyruvate oxidation in these rice seedling particulate preparations is indicated by results obtained when homogenates and supernatant fractions were assayed for isocitratase and malate synthetase.