In the language of law, it’s inevitable to make explanations on irregular actions and illegal phenomena. Thus, there must be some words and phrases in reference to reasons. This study makes a detailed comparison and analysis on the frequency of use and semantic prosody of these English words /phrases in legal English through Corpus of Contemporary American English (COCA) and Parallel Corpus of Chinese Legal Documents (PCCLD), including its mainland, Hong Kong and Taiwan sub-corpora, thereby revealing and summarizing multiple usages and rules of these phrases in legal English. The results show that there are misuses of these phrases as well as their negative semantic prosody. Suggestions are given for translation and writing of foreign legal documents in order to achieve accuracy in translation of foreign legal texts.