String searching algorithm is used to determine whether a word, a statement and a phrase exists in newspaper article, books, web pages or not. Especially as the volume of web pages and documentation increases, time and cost of searching a pattern increases. In this paper, we consider the characteristics of English alphabets combination in a pattern and a text(frequency and position of vowels in a pattern and a text), and propose new efficient string searching algorithm based on vowel composition structure of pattern and text. If a pattern has two or more vowels, proposed vowel-based string searching algorithm is more efficient at the both case of best matching case and worst matching case. Especially, a pattern's length does not affect performance of proposed vowel-based string searching algorithm. Only a pattern's location in a text can affect running time of algorithm. Proposed vowel-based string searching algorithm can avoid un-matching vowels in a text and un-necessary comparison between a pattern and a text. Therefore in reality, vowel-based string searching algorithm is usefully and effectively applicable to string searching function of a pattern and a text.