Understanding and pictophonetic characters. The word "Zi" did not exist in Oracle Bone Inscriptions in Shang Dynasty, but it did exist in Shang Dynasty. The inscriptions on bronze in Shang Dynasty (figure 1) and the inscriptions on bronze in Western Zhou Dynasty (figure 2) are the next words of Bao Mi. The "Zi" in Oracle Bone Inscriptions is like a baby; Mi, Oracle Bone Inscriptions is like a house. The structure of "Zi" is to simulate the appearance of a child born in a house, from which the seal script (Figure 3) comes. Although the strokes of official script and regular script have changed, the basic structure is still the same. Zi is represented by the combination of Zi and Mi, while Zi and Zi are similar in phonetics and also have phonetic meanings.