The task of translator is not merely transplanting or rendering the original into a foreign language, the success or failure of translating English poetry into Chinese depends on the translator's knowledge of poetry. This paper will first analyze the works of bad translation by classifying them into the following types: absurd translator, poor translator, perfunctory translator and commercial translator. The author will further discuss important elements of poetry indispensable for translator to understand poetry. These include poetic pattern, rhythm, pause, stress, breath, word orders, technique and structure.