The thermokinetic characteristics of the actions of Na~2SeO~3 and four kinds of ruoye polysaccharides on Escharichia coli and Aerobacter aerogenes have been studied by means of microcalorimetry. It was found that low concentration of Na~2SeO~3 and polysaccharides had promoting action on the growth of cells, and high concentration of Na~2SeO~3 had inhibitory action on the two bacteria, and ruoye polysaccharides did not show inhibitory action. For different drugs, the mechanism of action may be different. It was provided a lot of information on the bioaffect of selenium.

Key words: POLYSACCHARIDE, SELENIUM, SELENATE, SODIUM SALT, MICROCALORIMETRIC METHOD, THERMODYNAMICS, BACTERIA, GROWTH RATE, ENTERIC MICROORGANISM, ESCHERICHIA COLI