To the particular scores of interfaces in Visual Prolog, the specific functions and effects of mechanisms of support qualifications and open qualifications are analyzed and investigated in detail on the basis of study of principal issues of mechanisms of these qualifications. First, the fundamental notions of interfaces and objects are expatiated. Then, the functional mechanisms of support qualifications and open qualifications are exposed with a detailed analysis. Finally, the essential characteristics and application mechanisms of the interface score qualifications are exposed and illustrated through an instance.