This paper describes the English-Cantonese dictionary currently being compiled by the author. Its distinctive feature is the semantic classification of lexical entries under five main areas of 'Human Life', 'Language', 'Natural World', 'Numbers', and 'People' and a number of semantic categories and subcategories (e.g. the human body, bodily excretions, illnesses, physical conditions). The vocabulary comes from the daily colloquial speech of educated Hong Kong Cantonese speakers. The underlying rationale this grouping rests on studies from linguistics, semantics, psychology, neurolinguistics, and anthropology which have showed that human beings organize the lexical component of their mental grammars in complex relational networks. In addition, mental storage of lexical items also includes semantic relations of synonymy, meronymy, antonymy, homonymy, hyponymy, etc. The choice of some semantic categories has been influenced by the kinds of linguistic items that occur in both languages.