The aim of this study was to determine the good time point and substrates of soybean meal (SBM) and peanut meal (PNM) fermented with Saccharomyces cerevisiae. Thus, parameters of pH, yeast cells population, chemical compositions of fermented products after incubation were measured and evaluated. As a result, after 72h of incubation, (i) yeast cells population of SBM quickly reached near the highest value at 24h while that of PNM had to wait until 72h, (ii) the protein content of PNM increased by 3.68% while that of PNM only increased by 1.75% (P