In vitro experiments showed that sodium bicarbonate (SBC) was effective in inhibiting the growth of Mycogone perniciosa. The inhibition of radial growth, germination and germ tube elongation of chlarnydospores was 100.0%, 73.9%, 79.1 %, respectively, at 4% SBC. Complete inhibition of the germination and germ tube elongation of conidia was achieved by 4% SBC. Seven experiments were conducted to test the hi vivo efficacy of sodium bicarbouate and reduced dose of prochloraz manganese either alone or in combination. Treatments were applied to casing soil twice by drenching 2 h before casing and 2 days after casing. In seven in vivo experiments, the effect of SBC in inhibiting M. perniciosa wag inconsistent. The efficacy of the combination of SBC with reduced dose (10% of label dose) of prochloraz mangenese were not significantly and consistently different from that of the label dose of prochloraz manganese in inhibiting the disease and increasing the yield in three repeated experiments. Similarly, in the bags treated with the combination of sodium bicarbonate and reduced dose of prochloraz manganese, the amount of sclerodermoid masses were reduced to 309 g from 1048 g in the control. Sodium bicarbonate treatment neither impaired quality of sporophores nor reduced the yield.