Abstract: Lesson Study (LS) has been followed 35 Biology teachers at the Surakarta Junior High School (JHS), especially those teaching in grade eight and eight Biology Education students of UNS. The procedure of LS implementation are as follows: 1). Discuss the meaning and the purpose of using LS in relation to improving the quality of teacher’s work, the terms and commitments required. 2). Explain the guided inquiry strategies used to develop life skills and learning outcomes of the JHS students. 3). Model the strategy of guided inquiry. 4). Discuss the strategy that has been modelled. 5). Evaluate the guided inquiry lesson plan based on an evaluation tool of Forbes and Davis that has been modified. 6). A group of teachers do LS in peer teaching using the strategy of guided inquiry. 7). Revise lesson plans according to the input from teachers. 8) The Lesson plan then be implemented in real teaching by three teachers in three JHS, other teachers observe the real teaching and then discuss how to improve the lesson plans. 9). Revise other lesson plans that will be used for real teaching in the experimental research that implement the guided inquiry strategy. Implementation of the guided inquiry learning strategy in biology has been done during the second semester of 2011-2012 at two JHS samples. To maintain the consistency of the implementation of guided inquiry strategy by the teachers, at the time of the research peer teaching activities among Biology teachers in the LS format has been done for every material. The result of the research is that the teachers are considered ready and can properly implement the guided inquiry lesson plan in the real teaching necessary for treatment of dissertation research which has been shown from record of the fulfillment of guided inquiry syntax.

Key words: Strategi pembelajaran Guided Inquiry, SMP, RPP, Lesson Study