Many inorganic salts were studied for their effect on the ascorbic acid content of Mung bean sprout. With the view of the possible application of the experimental results on large scale bean sprout production, the chemicals studied were dissolved in the tap water used for soaking and daily flushing the bean during sprouting. The relation between temperature, length of the sprout and ascorbic acid content were also observed.It was found that Co(NO3)2, at a concentration of 0.001 M promoted ascorbic acid synthesis; and NH4NO3 at 0.01 M hastened the growth of the sprout. Other substances studied either exerted no positive effect on ascorbic acid production or depressed the growing of the sprout. When the temperature was between 10-15℃ and the length of the sprouts were 2 cm, ascorbic acid production was most favorable.