In order to explore a practical way of improving machine translation(MT)quality,the error types and distribution of MT results have to be analyzed first.This paper analyzed English-Chinese MT errors from the perspective of naming-telling clause(NT clause,hereafter).Two types of text were input to get the MT output: one was to input the whole original English sentences into an MT engine; the other was to parse English sentences into English NT clauses,and then input these clauses into the MT engine in order.The errors of MT output are categorized into three classes: incorrect lexical choices,structural errors and component omissions.Structural errors are further divided into SV-structure errors and non-SV-structure errors.The analyzed data shows firstly,the major errors are structural errors,in which non-SV-structural errors account for a larger proportion; secondly,translation errors decrease significantly after English sentences are parsed into NT clauses.This result reveals that non-SV clauses are the main source of MT errors,and suggests that English long sentences should be parsed into NT clauses before they are translated.