Decorative unit structure

A decorative unit structure comprising:

• a first decorative unit having a convex surface and a concave surface, a center of a bottom of the first decorative unit being formed with a central extension post facing the concave surface, a free end of the extension post being formed with a bulge end;
• and
• a second decorative unit having a convex surface and a concave surface, two sides of a bottom of the second decorative unit being formed with two extension posts spaced from each other by a certain distance and facing the concave surface, free ends of the extension posts being respectively formed with bulge ends, a bight bottom edge being defined between the two extension posts,
• whereby when combining the first decorative unit with the second decorative unit, the central extension post of the first decorative unit is extended into the space between the two extension posts of the second decorative unit with the bulge end of the extension post of the first decorative unit right abutting against the bight bottom edge of the second decorative unit, the two extension posts of the second decorative unit also extending to two lateral sides of the central extension post of the first decorative unit with the tops of the bulge ends of the two extension posts abutting against the bottom of the convex surface of the first decorative unit, whereby the central extension post of the first decorative unit and the two extension posts of the second decorative unit together form an inter-engaged structure having three supporting points which enable the first and second decorative units to be stably rested on a plane face.