1. Iwan Saskiawan
2. Nunuk Widhyastuti
3. Kasirah
4. Dodi Sutardi

Recently, Pleurotus ostreatus has become the most cultivated edible mushroom in Indonesia because of the simple in cultivation.  Pleurotus ostreatus easy to grow in a medium contained sawdust as a main substrate, with the addition of rice brand, corn flour, lime and gypsum. Mushroom production is bioconversion process which involves the activity of lignocellulolytic enzymes such as laccase, cellulase, and xylanase. The aim of this study was to reveal the pattern of laccase, cellulase, and xylanase activity during the growth of P. ostreatus on the sawdust medium. The results show that the highest laccase activity was obtained on the 15^th day after spawn inoculation (ASI) of 0.66 Unit and decline sharply after the day of 45^th ASI until the day of 75^th ASI. Furthermore, the similar pattern with difference on the time incubation was obtained on the activity of cellulase and xylanase. It was decrease after the day 30^th ASI. The highest activity of cellulase was 0.51 Unit on 30^th day of ASI and decrease gradually until the day of 75^th ASI. Furthermore, the highest activity of xylanase was on 30^th day ASI of 0.34 Unit and decrease sharply until the day of 75^th.