The so-called "contract nullification" is not a legal term, legal concepts, but in the process of contract signing, fulfillment and termination of the contract, there are often parties to this concept. The original intention and true meaning of this concept is to make the contract is null and void, not bound by the contract, do not assume the rights and obligations of the contract. However, the contract is signed at different stages, the contract written on the "null and void" words, the effect is not the same: (a) the contract discussion, finalization stage. If the two sides in the contract discussion, finalization stage, for the writing, printing of the manuscript, because in the continuous revision, correction, for the manuscript is not used to write "null and void", such a contract will be null and void; (b) both sides signed in the "null and void" words on the contract. (b) Both parties signed the contract with the word "void". This depends on the signature of the two sides of the true meaning of the expression, if the two sides of the true meaning of the expression is to sign a contract, and mistakenly signed in the contract with the word "null and void", should be valid. If the meaning is not to sign the contract according to this draft, should be invalid. (C) after the entry into force of the contract, fill in the "nullification" words, after the contract has entered into force, on both sides of the binding, if only write the "nullification" and can not simply end the contractual relationship between the two sides, or suggest that, separately written release or termination of the agreement instruments, or not necessarily lead to the invalidity of the contract. Otherwise does not necessarily lead to the contract is invalid. Article 155 of the civil code, invalid, revoked civil legal acts from the beginning of invalid or revoked civil legal acts from the beginning of not legally binding. Article 156 of the Civil Code, part of the civil legal act is invalid civil legal act is partially invalid, does not affect the effectiveness of the other parts, the other parts are still valid. Article 157 Legal Consequences of a Civil Legal Act Being Invalid, Revoked or Determined Not to be Effective After a civil legal act is invalid, revoked or determined not to be effective, the property acquired by the perpetrator as a result of the act shall be returned; if it cannot be returned or if there is no need for it to be returned, it shall be compensated at a discounted price. The party at fault shall indemnify the other party for the loss thereby sustained; if all parties are at fault, they shall each bear the corresponding responsibility. If the law provides otherwise, in accordance with its provisions. The contract established by law shall be legally binding on the parties. The parties shall perform their obligations in accordance with the agreement, shall not change or cancel the contract without authorization. The contract established by law, protected by law. If the contract is fraudulent, coercive or manifestly unfair, one can apply to the court to change or revoke the contract. In addition, the contract is an autonomous expression of meaning between the two parties, and the parties can cancel the contract by consensus. The law also provides for the right of unilateral rescission. The parties may rescind the contract under any of the following circumstances: (1) the purpose of the contract cannot be realized due to force majeure; (2) before the expiration of the period of performance, one of the parties expressly indicates or shows by its own behavior that it will not perform the main debt; (3) one of the parties delays the performance of the main debt and fails to perform it within a reasonable period after being reminded; (4) one of the parties Delay in performance of the debt or other breach of contract, so that the purpose of the contract can not be achieved. Therefore, after the contract is established and effective, there is still a chance to reverse the termination. The proof of invalidity of the contract is a matter for separate negotiation between the two parties to the original contract, and must be agreed upon by both parties. Only *** with the signing of the document proving the invalidity of the contract is legal. Otherwise, any unilateral signing of a certificate of contract nullity is illegal and invalid. The statement should note that the names of both parties should be consistent with the original contract. This article details the problems in the contract or disputes in the performance of the contract. If the contract continues to be performed, it will cause losses to both parties. To prevent future disputes, both parties agree to cancel the contract. The rights and interests of both parties involved in the original contract and all terms and conditions are mutually waived. This negotiation will come into effect after signed by both parties. This certificate is in duplicate, and each party holds one copy.