It’s a challenge to vividly introduce the job scheduling algorithms. To solve it, a method based on time-axis is introduced in the paper to describe them. Firstly, the allocation performance of system resources is shown clearly in the time axis. Secondly, the implementation procedure of“first come first served”scheduling algorithm and“shortest job first”scheduling algorithm are described visually in the time-axis. The results of teaching practice shows that this time-axis method is a useful way to teach the job scheduling algorithm in operating system.