The illumination of nature of notice period, as the time limit for the resignation of laborer or the advance notice of dissolution of employer, is related to the clarification of many practical issues. This thesis approves that the right of advance notice of dissolution is a kind of right of formation, whiling approving the inside property of theory of beginning period. And this thesis is not confined to the shackles of existing theories, when distinguishing the external property of theory of procedure and theory of prerequisite, and choosing the provisions concerning with notice period regulated by law, collective contract or contract of labor. Then this thesis presents that the regulations of notice period should be applied by distinguishing the subject of advance notice of dissolution according to specific circumstance under the guiding ideology of appropriately tilting to protect the interests of laborer and increasing the flexibility of labor market.