The authors propose a model for analyzing English sentences including coordinate conjunctions such as "and","or","but" and the equivalent words. Syntactic analysis of the English coordinate sentences is one of the most difficult problems for machine translation (MT) systems. The problem is selecting, from all possible candidates, the correct syntactic structure formed by an individual coordinate conjunction, i.e. determining which constituents are coordinated by the conjunction. Typically, so many possible structures are produced that MT systems cannot select the correct one, even if the grammars allow to write the rules in the simple notations. This paper presents an English coordinate structure analysis model, which provides topdown scope information of the correct syntactic structure by taking advantage of the symmetric patterns of the parallelism. The model is based on a balance matching operation for two lists of the feature sets, which provides four...