This study investigated elmentary school pupils' episodic memory of science laboratory work. Generally, pupils retain many episodes about past science experiments in their long-term memory. After taking a survey of 348 children, the results were as follows : 1) Pupils retain episodes which are affirmative rather thatn negative. 2) A considerable number of pupils retain a negative episode about insects and the human body. 3) Elementary pupils retain more episodes than secondary school students. It is important to provide children with affirmative episodes to improve their scientific ability. The teacher should be aware of their past experiences and organize experiments to create good memories in a positive atomosphere.