A pen having a 3-dimensional pattern has at least one flexible strip. The flexible strip is sandwiched between a pattern ring and a liner ring with the 3-dimensional pattern partially protruding out of the pattern ring from a corresponding through hole. The liner ring abuts a bottom end of a connecting ring. The connecting ring is formed with an annular flange on its outer surface. The pattern ring abuts the annular flange to enclose the liner ring. A top end of the connecting ring is clamped onto a barrel of the pen, and a bottom end of the liner ring is threadingly connected to a tip of the pen.