Abstract: Structural relative number is one of the most important indexes in the comprehensive indexes,and is widely used.The connotation of the theory and the algorithm seems to be perfect,but in the structural analysis,some puzzling situations often appear in operation,which suggests the presence of defects in the structural relative number.In this paper,through elaborating connotation,listing the typical examples,presenting the problems,and analysing the cause of the problem,it is pointed out that the general basic structure and derivative structure must be distinguished,further refinement must be made in the aspect of algorithm,exceptions must be provided for calculating the derived structure,so that the needs of various statistical analysis can be met.

Key words: structural relative number, refining, improvement, inexplicability