Vagueness is one of the basic characteristic of natural language. Vague language is employed widely in advertising language. In this research cosmetic advertisements in Chinese and English magazines are selected and analyzed. The results show that in Chinese and English cosmetic advertisements vague adjectives are the most frequently adopted, and that vague nouns and verbs are employed greatly. Comparatives, superlatives, hedges, numerals, quantifiers and pronouns are also used in advertisements.