Abstract: Price reduction liability has an important function to balance the parties' interests，which is the best way of relief for the other party who can't cancel the contract and prove actual loss when one party defectively performs the contract. The charac- teristics that individual owner can't rescind the contract and prove the actual loss when the service enterprise defectively performs the realty service contract highly match the application of price reduction liability. If we excessively consider realty service contract's group characteristics and hold a conservative attitude in judicial practice，it will violate the principle of fairness and al- so is not conducive to the development of realty service industry We need to strictly apply the price reduction in accordance to the realty service company's responsibility and the drawbacks of the actual service levels． If the realty service has serious flaws or socioeconomic status，we should be determined to reduce the price．