Abstract: Knowledge acquisition from text(KAT) is one of the important research problems in knowledge engineering.How to acquire a special kind of knowledge-mereological knowledge from large-scale Web page text is the research emphasis in this paper.Firstly,six different types of mereological knowledge are introduced,on the basis of that,grammatical patterns could be acquired automatically or semi-automatically to construct the extraction pattern base.Then quasi-concepts would be extracted and verified locally with those result files generated by patterns.At last,mereological graph is defined to verify all the quasi-concepts globally based on graph theory,which has been proven to work well by experiments.