Abstract: Author systematically answers some questions on mechanical essence of deforming rule in the mechanical analysis field of superplastic tensile forming, which is mostly based on the author’s works in this field. Emphasizes the measure methods of strain-rate sensitivity index m and strain hardening index n, subtly analyzes impact of deforming path on n and m, which is based on typical deforming paths and introduces constitution equation of variable parament superplastic ensile forming. Finally brings forward his opinion on some attentional issues in the field of superplastic research. Aims at intercommunion with colleague and fellow-scholars’ rectification.

Key words: Constitution equation, Strain hardening index, Strain-rate sensitivity index, Superplastic