Miscanthus is a promising source of bioenergy with high lignocellulose content. This paper studied the effect of hydrothermal pretreatment on Miscanthus biogas production. Different pretreatment temperature from 125 to 200 degrees C was tested. After pretreatment, hemicellulose was partially removed and this led to a change in cellulose accessibility. Enzymatic hydrolysis was used to examine the digestibility of different samples. There was no obvious enhancement in low temperature (125 and 150 degrees C) conditions. According to the results, 200 degrees C hydrothermal pretreatment was the optimal condition saving 50% on the digestion time and increasing glucose production 13.2 times compared with the raw material. Although the cellulose crystallinity increased after the pretreatment, its effect on biogas production and enzymatic hydrolysis was limited. (C) 2016 Published by Elsevier Ltd.