Which language is more important in Hong Kong?

Mandarin. Hong Kong has already become an international city. Although English is still important in Hong Kong, Mandarin is becoming an important language in Hong Kong due to the the business and culture interactions between Hong Kong and China since 1997.

Actually,both are important in Hong Kong now because there are some many Chinesemen come to Hong Kong and we need to know more about Mandarin.And also,English is the international lanuage so that we need to learn it too.