Under the Civil Code and related law in Korea, the liability for defects after delivery belongs to the Contractor. However, various disputes have occurred in relation to the remedy of such defects and the compensation for damages, which are the main liability of a contractor in the event of defects. Despite court decisions regarding defect liability, many problems prevail in the real world. For this reason, this working-level research considers the introduction of a performance warranty contract system. To establish the system successfully, it is necessary to analyze the trend of various warranty cases in the US. Therefore, the warranty system of the US was first examined, and the effect of acceptance, notification and burden of proof, remedies under warranty clauses, and default termination were investigated and analyzed in this study.