Translation lexicons are fundamental to natural language processing tasks like machine translation and cross-language information retrieval. This paper presents a lexicon builder that can auto-extract (or assist lexicographer in compiling) the word translations from Chinese-English parallel corpus. Key mechanisms in this builder system are further described, including co-occurrence measure, indirection association resolution and multi-word unit translation. Experiment results indicate the effectiveness of the authors method and the potentiality of the lexicon builder system.