Abstract Emotions are important part of human communication. In this paper emotion is automatically detected from text. Understanding the meaning of language is the goal of Natural Language Processing and also understanding emotion is one of goals of affective computing. Those two areas of artificial intelligent have recently come together for understanding emotion in text. This paper describes a English emotion ontology based on WordNet and its construction. The ontology is used to understand, classify and recognize emotion in English sentence. Using the ontology the emotion will be predicted by Natural Language Processing.