The influence of hydrophobic poreblocking ingredient (HPI) on the workability,mechanical property,and durability of concrete with different strength grades is studied.The research result shows that the HPI can improve the fresh concrete’s workability and reduce water absorption of concrete significantly by more than 50%.The HPI can enhance concrete chloride ion’s penetration resistance at the same time.It can reduce the early concrete strength,but it has no obvious difference at the later stage.The PI was used in Fanhegang bridge and Donghua bridge and improved the durability of concrete structure significantly.