The purpose of this research is to develop measurement instrument of scientific reasoning tests for biology education students. The research method used the development stage of the instrument based on the test development procedure according to Oriondo & Dallo-Antonio including: (1) design of test, (2) trial test, (3) determination of validity, and (4) determination of reliability. Test instrument sheet consisting of 13 items and then validated by promotors and measurement experts. The validated instruments were then tried out on 100 students in Biology Education Program of UIN Sunan Kalijaga Yogyakarta. The polytomous data were analyzed using Partial Credit Model (PCM-1 PL). The results showed that 13 items of scientific reasoning instruments were proved fit with the PCM model. By using the lowest limit criteria, INFIT MNSQ was 0.77 and the upper limit was 1.30, the instrument reliability was 0.74 that based on the estimate of case estimate was high. The index of difficulty of items ranged between -2.25 and 0.97. Thus, scientific reasoning instruments which were qualified to measure scientific reasoning skills should be prioritized in learning for biology education students.