Associated with the carbonization of glucose in the hydrothermal process, MoS2/amorphous carbon composites were synthesized by a one-step hydrothermal method and characterized by various technologies. Introducing carbon into MoS2 increased its surface area and enlarged the edge-to-corner ratio of the MoS2 slab of the MoS2 phase, which contributed to a high deoxygenation degree in the hydrodeoxygenation (HDO) of p-cresol, but excessive carbon covered some MoS2 edges that acted as active sites for HDO reaction and lowered the conversion. The presence of water modified the surface structure of MoS2 and had a great effect on the HDO activity and product distribution. During the HDO reaction, sulfur oxygen exchange at the edges of MoS2 resulted in the loss of S atoms and the intensity decrease of the (002) diffraction peak for MoS2 phase, which was accelerated by increasing the amount of added water. Carbon in MoS2 only acted as a support and had no preventing effect on water. When the added water was 0.2 g, i.e., water/p-cresol molar ratio was 0.5:1, after reaction at 275 degrees C for 8 h, toluene selectivity and deoxygenation degree increased to 91.3% and 94.2%, respectively.