Abstract: Based on the fixed-point theorem,a new method to treat the priori order was proposed in order to unify and extend the different answer set semantics resulted from different ways of dealing with the prior order in logic programs with a rule order.With this method,the rule order was taken into account in the iterative procedure of rules.As a result,nine kinds of answer set semantics were obtained,and the correlation between them was discussed in detail.It was proved that those nine semantics do not form a linear structure but a normal lattice structure.Furthermore,in ordered stratified logic programs,all of the nine answer set semantics become the normal answer set semantics.