The paper examines the historical change in linguistic practice of Hong Kong advertising through the decolonization period and attempts to make sense of it from a local-and-global point of view beyond the conventional national-functionalist perspective. It is found that the prominent patterns of language mixing in the advertising of Hong Kong are not only 'Standard Written Chinese mixed with English', but also 'Standard Written Chinese mixed with both English and Cantonese'. The embedded elements of both English and Cantonese in the Chinese advertisements can take the form of a word, a phrase and/or a full clause and can serve both informational and involving functions. Finally, it is argued that multilingual mix in Hong Kong advertising is a phenomenon constantly emerging in the multicultural process of globalization and that being able to mix different languages or varieties of languages for effective communication should be an aspect of linguistic competence highly valued in the age of globalization and localization.