Abstract: In this article, the two-dimensional Einstein theory of relativity in college physics, and Minkowski space-time diagram is applied to teaching of the there is an intuitive reveal on the inner connections between simultaneous relativity and space-time in special relativity as well as time dilation and length contraction.

Key words: teaching of the Einstein theory of relativity, two-dimensional space-time diagram, simultaneous relativity, time dilation and length contraction effect, intrinsic connection