The objectives of this research are : (1) The influence application of the learning based problem through guidance to the ablity of the student critical think at the main biodiversity. (2) The influence application of the learning based problem through guidance to result study at the main biodiversity (3) The raising application of the problem based learning trough approach inquiry guidance to the ablity critical think the result study can be dilentatisme of value n-Gain the result study at the main biodiversity.The population is this observation on the students guide Xa and class Xb. The method which used is the problem based learning at the experiment class and communication method at control class. The plan of this observation is "one group pretest-posttest design". Technic analysis different test with programme SPSS 16. The result of this observation show that : (1) Presence was influence application of the problem based learning trough approach inquiry guidance to the ablity critical think refer to t-test 0,0025