In this article, four pairs of hexagrams are chosen out of the sixty-four ones in The Book of Changes to analyze how every pair of them is meant to show the concept of "vigilance in peacetime." Among the four pairs, the hexagrams in two of them are opposite to one another, such as the Small Buildup Hexagram and the Treading Hexagram, the Richness Hexagram and the Travel Hexagram, while the ones in the other two pairs are continuous with one another, such as the Great Possession Hexagram and the Humility Hexagram, the Great Buildup Hexagram and the Nourishment Hexagram. The fact that common conclusions can be drawn out of these two different relationships shows the general application of this concept from The Book of Changes Certainly, other than :Vigilance