Foreign trade is an indispensable activity in the globalization era. Researching the liabilities of parties in performing the sale contracts and the avoidance right of parties in the contracts is a vital issue. Therefore, this article compared Vietnamese Commercial Law 2005 with the United Nations Convention for the International Sale of Goods (CISG) and Principles of International Commercial Contracts (PICC) regarding the avoidance of sale contracts, including the three aspects, fundamental breach, failure in performance obligations of contract at the end of adding time, and anticipatory breach. The findings not only enable Vietnamese merchants to master international rules in establishing foreign trading but also show differences and similarities between Vietnamese law and international rules. By doing that, this article puts forward some implications for rebuilding the definition of “fundamental breach” in Vietnamese commercial law. Also, this paper suggested that the avoidance clause of the Vietnamese law should include the claim to terminate the agreement of the innocent party due to the non-performance party’s failure to fulfill contractual duties at the end of adding time, and the other party will be constituted an “anticipatory breach”.