Descriptive Answer Evaluator (DAE) evaluates technical descriptive answer against given correct (model) answer and to assign appropriate marks with the help of evaluation criteria in form of rules. Candidate normally writes answers in using one’s vocabulary and style. Ideally, natural language understanding is required for such a task. But it is currently an open challenge problem. The approach followed by us includes deriving key concepts and their description from the model answer as well as from candidate answer. Candidate’s key concepts and description are matched against those of model answer and there by evaluation is carried out. In this process, we have addressed synonym problem, handling of compound/complex sentences, conversion of passive voice sentences to active voice etc so as to facilitate the matching and evaluation process. DAE compensates for minor grammatical errors. The expected outcome of DAE is to assign marks to candidate answer as close as manual assessing of answer sheets.