Abstract: A new method to detect vowel is introduced in this paper. The method is based on spectrum analysis of speech signal requiring no learning process. More importantly, this method can be used in many languages. The method is tested utilizing the data subset of the OGI multi-lingual telephone speech database, and the data subset includes four language: English, Putonghua, French and Japanese, then an improved method is also provided. Finally the result of the vowel detection rates among the four languages is given. The experiments show that this method is effective.