This research studied the increasing of nutritional content in cassava starch fermented with P. ostreatus (Jacq.) P.Kumm. and L. squarrosulus Mont. The cassava starch waste was supplemented with maize grain, paddy rice, rice bran, broken rice, and soybean meal at 0, 10, 20, and 30%. Solid state fermentation was carried out for 28 days. The results showed that highest reduced sugar at 86.09 g/L was found in cassava starch waste 70% + rice broken 30% fermented by L. squarrosulus Mont. The highest protein content at 127.92 g/L was found in cassava starch waste 90% + soybean meal 10% fermented with cassava starch waste 70% + rice broken 30% for 14 days. It is concluded from this experiment that P. ostreatus (Jacq.) P.Kumm. and L. squarrosulus Mont. can increase nutritional content in several feed mixtures.