This study aimed to examine the impact of mushroom extract-based solid media on the β-glucan content, growth rate, density, and biomass content of <i>Pleurotus ostreatus</i> (oyster mushroom) mycelia. Fresh, high-quality raw <i>P. ostreatus</i> were washed, sliced, and heated in a sealed pressure cooker at 90°C for 4 h in the drying cabinet. Following the heating process, centrifugation was carried out. Different concentrations of <i>Pleurotus ostreatus </i>extract were mixed with distilled water (0%, 25%, 50%, 75%, and 100%) and prepared for a sterile solid media. A malt extract-based medium was maintained as a control. This study focuses on the growth performance of <i>P. ostreatus</i> mycelium on its own mushroom extract-based culture medium which holds considerable economic and environmental significance. During the six-day observation period, the mycelium exhibited consistent growth across all tested media, maintaining a steady growth rate of 15 mm. The increased content of mushroom extract resulted from the enhanced density of the mycelia and biomass content. It can be inferred that when media containing less than 25% of mushroom extract dilution is used, β-glucan can be formed in smaller amounts. Further research is needed to explore mushroom extract derived from different types of mushroom byproducts, which fail to meet commercial standards.