Traditional researches on the similitude between entities are excessively simpli fied and lack of intent. In this paper, firstly a detailed analysis on the analo gical relationship between entities is made, which concerns about not only the c ommon attributes, but also the redundant and conflicting attributes of analogica l entities, and it is explained from the point of view of extensive pertinence. Secondly different extensive similitudes are defined based on different decision -making principles, which coincide with different demands in decision-making c ircumstance. Finally a set of generalized logical operator combination rules in analogical reasoning is proposed, therefore this proposal remedies the limitatio n of invariable operation rule in conventional analogical reasoning.