Hunston (2008) puts forward the concept, constituents and research methods of studying 'semantic sequences',which refers to "series of meaning elements" that occur regularly in a corpus. They are therefore more usefully characterized as sequences of meaning elements rather that as formal sequences. This paper applied this theory to explore the semantic sequences based on the collocational framework " the * of" in medical English and biographical English. The findings show that the collocational framework forms the semantic sequences relating to treatments, diseases, changes and so forth in medical English, and forms the semantic sequences relating to life, experiences, time and the like in biographical English. Hence, these semantic sequences can reflect the features of different genres and can be used to distinguish between and predict different genres.