An exceptional finding in 2013 was four wooden pattern looms excavated from a Han dynasty tomb at Laoguanshan, Chengdu. These looms date back to the second half of second century B.C. Each loom has a toothed beam with two tenons which can carry the hook beam moving in warp direction and stop at a certain position to select a pattern shaft. One loom has two sliding frames. When one side the axle treadle held by the front poles, the other side turns up to push two sliding frames in the slotted roles upwards. The hook beam on the top is also pushed up by two frames. The other three loom models have hook rods on either side. When the weaver steps on one side of the axle treadle, the other side pushes the hook rods upwards, and the hooks lift the pattern shaft. After careful examination of both types of loom, it is found that the sliding frames power transmission loom could been used to weave longer patterns, while the two hookrods loom could make it easier to weave but produce a shorter pattern. These two types of loom are the earliest examples of looms in China. They represent the knowledge and creativity of ancient Chinese people.