Assessment is alaways a main issue of school educational reform. It is also one of teachers's main professional behaviours. This study is to investigate German elementary school teacher's concept and practice in assessment. Its result will be compared with the other processing studies on the same issue among Taiwan, Australia, the United States and the Great Britain. With the focus on German elementary school teachers (Grundschullehrer), this study tries to: 1) examine the latest development and the evolutionary factors in German educational assessment; 2) to shed some light on the German elementary school teachers' understanding and explanation on the implication of assessment and related topics as well as the reality of it in instruction in terms interview and observation and 3) to analyze the effects of school context on elementary school teachers' concept and practice in assessment. Through literature review, interview and observation, this study firstly develops a questionaire fit for the implementation of "backward mapping" in development of elementary school reform and finally fulfill the ideas of educational evolution.