Promissory prohibition of business strife agreement is the premise of promissory prohibition of business strife obligation, and the promissory prohibition of business strife agreement is the basis for the demission employees to take on their obligation. Besides the conditions for the general agreements to go into effect, there are some other conditions and restrictions for promissory prohibition of business strife agreement to take effect. Only the legality and reasonable promissory prohibition of business strife agreement has force and effect and those promissory prohibition of business strife agreement which offend the law or go against rationality belong to invalidation agreement, and has no sanction.