The purpose of this research is to improve students\u27 learning activity and the result through LKS and learning strategy based on Predict-Observe-Explain (POE) on Archimedes Law in class VIIIA of SMP Negeri 2 Sanggau. This research is a Classroom Action Research (CAR) which done in two cycle with two meetings. Every cycle has four steps, planning, implementing, observing, and reflecting. The subject of this research are 30 students from the destined class. In collecting the data the researcher used observation paper and test item. The result shows that there is an improvement in students\u27 learning activity in the active stage and very active stage from 1st cycle to the 2nd cycle that is 6,66%, from 66,67% to 73,33%. This improvement affecting the result if students\u27 learning activity to reach the KKM from the 1st cycle to the 2nd cycle that is 3,33%, from 90% to 93,33%