Abstract: Water blocking generally exits in tight gas reservoir，which impacts production severely，water blocking experiment is carried out by using real rock core to study influencing factors，which includes average pore throat radius，drawdown pressure，the sort and content of clay mineral and relative permeability curve conformation.The conclusions show that reservoir permeability and the sort and content of clay mineral are the most important factors impacting exploration.
Key words：tight gas reservoir;water blocking damage;reservoir

Key words: tight gas reservoir, water blocking damage, reservoir permeability, drawdown pressure, clay mineral, phase permeability curve