In the course of the amendment of the marriage law, the duty of the mutual loyalty between spouses was widely concerned and caused many controversies. Although these controversies gradually subsided with the enactment of the new marriage law, this issue is now still heatedly focused because of the disability of protection for the duty of the mutual loyalty between husband and wife in juridical practice. This article, through the analysis and probe of this duty from its legal character, the present situation of its legal protection and the improvement approaches, holds that the loyalty of husband and wife to each other is a kind of status rights, with the nature of personal right, and also belongs to the scope of claim rights; the system of compensation for damage should be established to improve its poor legal protection in current juridical practice.