Abstract: Injection water is a usual way in oilfield development, the experimental study on the impact of injection water quality on flow capacity in low permeability reservoir of Weizhou were carried to conduct the water injection operation.The phenomenons are found that clay minerals, suspended solids, bacteria and seawater have large impact on the flow capacity.After water flooding, cemented clay mineral content decreased, skeletal mineral component content increased, particle migration mineral content decreased, lattice expansion mineral content increased.The results are the lower core permeability, the greater the damage to production capacity; larger the particle size, the greater the damage to production capacity; higher particle concentration, the greater the capacity of the injury.Sea water and the bacterial content of sea water have a lot of damage to flow capacity.