Abstract: P-sets(packet sets) are a dynamic model obtained by embedding the dynamic characteristics into the finite Cantor set X and improving it．P-sets are a set-pair composed of internal P-set X(internal packet set X) and outer P-set XF(outer packet set XF),or (XF,X) is P-sets．P-reasoning is composed of internal P-reasoning(internal packet reasoning) and outer P-reasoning(outer packet reasoning)．Using internal P-sets and internal P-reasoning,the paper gave the concept and characteristics of internal P-information recovery,internal P-reasoning generation and attribute hiding of internal P-information recovery,information elements supplemented theorem and dependence theorem of internal P-information recovery,attribute hiding theorem and attribute hiding discovery theorem of internal P-reasoning information．Based on the results,the application of internal P-reasoning information recovery in the information system was given．

Key words: P-sets,P-reasoning,Internal P-reasoning information recovery,Recovery dependence theorem,Attribute hiding theorem,Attribute hiding discovery theorem,Application