This paper is based upon a five-year research project on a new attempt at post-editing of machine translation (MT).The research identified the MT error patterns of a text corpus of 100 000 sentence pairs of a car maintenance manual and did statistical analyses of the MT errors.Examples are used in this paper for illustrations of the error patterns.Our statistical analyses reveal that the MT errors reach as high as over 80%,and among the MT errors lexical errors stand at 70%.This research explored a cutting-edge attempt at MT post-editing and was of great significance in improving the MT quality and efficiency as well as lowering the MT cost.