The fungus-flora of 75 samples of surface soils from various parts of Manitoba has been analyzed. The population of fungi in these soils is abundant and varied despite climatic conditions which might appear unfavorable. Forty-four genera and 100 species of fungi have been identified, and the relative frequency of each determined. It has been found that the methods of soil microbiology give data regarding the parasitic as well as the saprophytic fungi in soils; that Trichoderma lignorum parasitizes certain other fungi, and thus may play a part in keeping in check the pathogenic fungi within a soil; and that the addition of chemical fertilizer to a soil results in a prompt and consistent increase in the fungus-flora.