This study aims to determine the differences in Science Proses Skills (SPS) of students using inquiry training learning model and conventional learning about the subject matter of elasticity and Hooke's law in High School. This type of research is a quasi-experimental with two groups of pretest-posttest design. The population of this research is all students of class XI MIPA in Public Senior High School 5 Medan. The sample was taken by a purposive sampling technique that consists of two groups, namely an experimental group and a control group. The data collected technique has been done by tests and observations activities SPS student. The data in this research was analyzed a hypothesis-testing t-test. The results showed significant differences in SPS between the application of using inquiry training learning models compared to conventional learning with the value of sig. was 0.000 at the significance of level 0.05. Based on the results of the N-Gain Score test with the application of the inquiry training learning model is higher in increasing SPS of the students by 0.70 in the high category compared to SPS of students with the application of conventional learning by 0.59 in the medium category.