The study is to analyzing the first and second APX tests of all subjects based on the difficulty and item discrimination in the class test theory. This includes total of four subjects, Mathematics, Physics, Chemistry and Biology. It turns out that the second mathematical test difficulty and item discrimination is more balanced compared to the other seven test sheets. Moreover, the test takers are divided into regular high school students and elite high school students. We observed that the overall performance of the elite high school students are better than the ones of regular high school, so as to decide whether should be classifications in the future APX. Lastly, we did a analysis of mathematical test to discover the gap between the actual difficulty to the test takers and the difficulty the proposotion professor set. The results reveal the fact that the high school students nowadays did more poorly on Linear algebra and Calculus.