With the shape of trapezoid, this Qijia Culute jade knife is seen five different size holes with unidirectional drilling on the upper part of the blade. Both sides of the blade have shown convex profile. Antiquity evidences include additive crystal, cleaving vein and differential weathering. In addition, the back end of the knife is seen calcification phenomenon. One of the hypotenuses is seen several small cracks owing to the effects of ages.(Right image is the location for Reman reading )本器由齊家文化當地白玉製成, 呈扁梯形, 刀背較厚, 有大小不一, 排列不整齊, 單向鑽成之五孔, 全器有增生晶體, 冰裂紋, 石灰沁等古玉跡象.