Two parallel lab-scale expanded granular sludge bed (EGSB) reactors were employed to evaluate the granulation of hydrogen-production sludge. One reactor was inoculated by a mixture of anoxic sludge and anaerobic sludge,the other by anaerobic sludge. By keeping temperature at (35 ±0. 5) ℃,hydrogen production rate (HPR),distribution of granular diameter,liquid end products and other parameters by the end of start-up stage were examined with the organic loading rate (OLR) increased. It was found that there was an easier granulation in the mixed sludge inoculated reactor. The medial diameter of granules and the HPR in the mixed reactor were 1. 25 times and 1. 23 times of those in the anaerobic one by the end. Both reactors formed ethanol-type fermantation,which suggested that fermentation type was not influenced by seed sludge. By the end of start-up stage,pH was 3. 9-4. 3 in the mixed sludge inoculated reactor and 4. 0-4. 4 in the other reactor. The mixed sludge inoculated reactor also maintained a higher volatile suspended solids (VSS) concentration of 27. 2 g/L than that of 24. 1 g/L for the other reactor. It is indicated that better granulation contributes to the high HPR and stable-running of the hydrogen production reactor. Moreover,mixture of anoxic sludge and anaerobic sludge is a better choice for inoculation.