Abstract: The induction time, formation time and pore water "memory effect" of methane hydrate were investigated in seven kinds of quartz sand with different particle sizes under initial pressure Pin=13.0±0.2MPa with supercooling degree Tsup=14.2±0.1K. The results show that the induction time reduces significantly than that in bulk water, and the induction time increases with the decrease of particle size. Also, the induction time is greatly reduced when subjected to pore water "memory effect" and the results are random. The influences of particle size and pore water "memory effect" on formation time of methane hydrate are similar to those on induction time. The quartz sand particles provide more nucleation cores, while methane diffusion is hindered by small pore size.