Exploring Critical Thinking And Students Curiosity Through Simple Inquiry Laboratory Activity. This study is a preliminary research to explore critical thinking skills and students curiosity of primary school in understanding science through simple inquiry laboratory activities. Participants are 20 students of 4th grade from one of the primary schools in Bandung. The researcher uses descriptive method to describe student activity during learning, student idea, and student's response in learning, obtained through personal communication, student worksheet and questionnaire. In the first lab activity, researchers used plasticine to explore students' ideas for design 3 objects for exploring science concept namely "floating, drifting and sinking. In the second activity students are directed to apply the concept that has been obtained in the first activity, which is they should selecting and classify red bean and corn with good quality and bad quality that used to be seeds. The results show that critical thinking ability and students curiosity begin look when they design objects that are expected for floating and drifting. Students are enthusiastic about experimenting and trying to recreate if their plasticine design fails. Trial and error activities are also stimulate them to continue their idea to find the right design objects. That concepts can be applied by student in daily life to select and classify seeds with good and less quality, and they are enthusiastic to plant it and compare it growth. Results also show that students enjoy  learning, not sleepy and bored, and feel challengedExploring Critical Thinking And Students Curiosity Through Simple Inquiry Laboratory Activity. This study is a preliminary research to explore critical thinking skills and students curiosity of primary school in understanding science through simple inquiry laboratory activities. Participants are 20 students of 4th grade from one of the primary schools in Bandung. The researcher uses descriptive method to describe student activity during learning, student idea, and student's response in learning, obtained through personal communication, student worksheet and questionnaire. In the first lab activity, researchers used plasticine to explore students' ideas for design 3 objects for exploring science concept namely "floating, drifting and sinking. In the second activity students are directed to apply the concept that has been obtained in the first activity, which is they should selecting and classify red bean and corn with good quality and bad quality that used to be seeds. The results show that critical thinking ability and students curiosity begin look when they design objects that are expected for floating and drifting. Students are enthusiastic about experimenting and trying to recreate if their plasticine design fails. Trial and error activities are also stimulate them to continue their idea to find the right design objects. That concepts can be applied by student in daily life to select and classify seeds with good and less quality, and they are enthusiastic to plant it and compare it growth. Results also show that students enjoy  learning, not sleepy and bored, and feel challenged.