Jiuxing xuefa 九星穴法 "Methods of [discovering the influence of] the Nine Stars on cavities" is a book on geomancy (fengshui 風水) allegedly written by the early Song-period 宋 (960-1279) master Liao Yu 廖瑀 (943-1018), courtesy name Boyu 伯禹. It is said that at the age of 15 sui he knew the five Confucian Classics (wujing 五經) by heart and was therefore dubbed Liao Wujing 廖五經. As a geomancer he was able to detect a bonanza and thereupon adopted the style Jinjing shanren 金精山人 "Mountaineer of the gold essence".
The 4-juan-long book Jiuxing xuefa describes the influence of the "Nine Stars" or Planets (jiuxing 九星) on the energetic nodes (xue 穴, literally "cavities") that are auspicious spots in the landscape. The Nine Planets are the sun (taiyang 太陽 "Great Yang"), the moon (taiyin 太陰 "Great Yin"), Venus (jinxing 金星), Mercury (shuixing 水星), "Purple Energy" (ziqi 紫炁), "Heavenly Funds" (tiancai 天財), the trinity "Concave Brain" (aonao 凹腦), "Double Brain" (shuangnao 雙腦), and "Flat Brain" (pingnao 平腦), and the constellations Tiangang 天罡 and Zaohuo 燥火.
All these "planets" were believed to effect nine functions and shapes in the landscape that were compared with the human body, namely "regular corpus" (zhengti 正體), "open mouth" (kaikou 開口), "hanging breasts" (xuanru 懸乳), "curved legs" (gongjiao 弓腳), "double arms" (shuangbi 雙臂), "single limbs" (dangu 單股), "inclined brains" (cenao 側腦), "boneless spots" (mogu 沒骨), and "flat faces" (pingmian 平面). For each of these relations, the Jiuxing xuefa provides annotated illustrations. The author makes the critical point that negative forms can be changed into auspicious ones. Edges and points in the landscape, for instance, can be changed into round forms that are not poisonous but auspicious.
The author presents the interesting view that man is not influenced by the energies of the landscape; rather, he can influence the energetic form of the landscape. This is possible by choosing one auspicious spot, from which the surrounding environment can be changed to such an extent that even less auspicious matters can be transformed into positive ones. This method was praised by some experts, while others doubted that such a transformation was possible.
The origins of the Jiuxing xuefa are very obscure, and it might be that the real author was someone other than Liao Yu. The book's scholarly approach is also somewhat heterodox. Nevertheless, it is included in the series Dili daquan 地理大全.