Conventional methods for storing and reproducing task are based on only the information of the actuators in the robot. However, in these methods, reproducing the stored task is difficult when the environment differs from that in storing phase. This is because these methods consider a meaningful task as just a motion. In this paper, to reproduce a stored task even if the environment differs from that in storing phase, storage and reproduction of a task based on the controlled variable of a task is proposed. To verify the principle of this proposal, the water pouring task is considered. The proposed method can reproduce the water pouring task even if the initial weight of the water in the bottle differs from that in storing phase. The validity of the proposal is confirmed by experiments using one degree-of-freedom robots.