Secret protection is studied after introducing the quantifying permission idea in the view of access control. Meta-Permission is derived from the view of ‘uality’and‘uantity’in philosophy. Compared with traditional cognition and permission used in access control, it comprehensively and deeply reflects the essence of permission. Combining with the threshold idea and RBAC, a threshold access control scheme based on quantifying permission is proposed. This scheme is applicable as widely as secret-sharing scheme, and shares the same function in protecting secret. Furthermore, it has some distinct advantages such as no relation in knowledge between the secret pieces hold by participants and the protective secret target, the ability for expressing the difference among participants?trustworthiness, and the low complexity in computing.