Button mushroom (Agaricus bisporus) is the most commonly used food crop around the world. According to the latest figures from the World Food Organization (FAO), in 2016, about 150,000 tons of mushrooms are produced in Iran. Across the globe, white mushroom pests and diseases annually cause major damages to the production of edible mushroom. Among them, the dry bubble disease caused by Lecanicillium fungicola is the most important disease of A. bisporus. In fact, L. fungicola has a longer developmental growth period in in vitro tests as compared with in vivo conditions which contributes to further difficulties in subsequent tests of biocontrol tests. Therefore, the objective of this study was to compare PDA culture medium and PDA medium combined with different materials affecting the growth rate of the pathogenic fungus (exist in the compost). In this regard, PDA culture medium were enriched or replaced with a range of ingredients such as wheat straw, rice bran, sawdust, sugar cane bagasse (10, 20 and 30% , and replacing potato extract) of sugar beet molasses (in quantities of 5, 10 and 20%), and 20 gr dry matter of A. bisporus. The mycelial growth of isolates were measured at 23±1 °C as compared to the other treatments and control (PDA). The results showed that the PDA medium containing 5% beet molasses with an average of the growth rate of approximately 7% is the best culture medium for the growth of L. fungicola as compared to PDA. Furthermore, other enriched or substitute culture media had the same vegetative growth as PDA culture medium and even less.