This research was backgrounded by problem in 4th grade of primary school that is lack of critical thinking ability of student on social studies learning. It means the learning not really enough involved all the potentials that student have, I's only demanded until low stage of thinking such as memorizing or copying text from the book so the learning process seems like meaningless. Therefore it must have founded the solution from that froblem, one of them is application guided inquiry model character based, this model could improve learning pattern that more interactive and meaningfu, tudent is demanded to solving problem and they are able to knowing the solution from the problem. Character education also lack from developed learning process. It is from the student attitude which is lack of curioussity, critical, independent and responsible of any act. This research aims to know the learning process by using guided inquiry model character base on social problem learning, critical thinking ability and accomplishment of learning by using inquiry model. Character values that used are clever, care and strengh. The method of this research is classroom action research with Jhon Elliot design on 3 cycle of implementation. Isntrument of research are observation sheet, interview, filed note, test and documentation. Quantitative data is used to knowing the average of critical thinking that student accomplished. Meanwhile qualitative data is use to knowing the process that interpretated on descriptive from. The result of researh showed there is improvement of critical thinking ability of student. Score in the cycle 1 is 49,6, score in the cycle 2 is 65,5 and score in the cycle 3 is 76,3. Based on thr result, it os recommended to use guided inquiry model character based as alternative learning model impove critical thing ability of student.