In vitro evaluation of three salts of copper viz. copper sulfate (CuSO₄), copper chloride (CuCl₂) and copper oxychloride [CuCl₂.3Cu(OH)₂] was done to check the effect of these compounds against three soil fungi namely, Aspergillus oryzae, A. niger and Drechslera tetramera. The data recorded at the end of incubation period revealed a remarkable decrease in fresh and dry biomass of these fungi by the action of all salts of copper. A. oryzae showed maximum suppression in growth in response to these treatments especially to copper sulfate, while A. niger showed the least.