Yanshan period igneous rocks occur extensively in the Hebei—Shanxi—Liaoning area, and a suit of ultrapotassic peralumino us porphyry can be recognized from them. They are composed of ryhyol ite porphyry, quartz porphyry and quartz feldspar porphyry,of hypabyssal a nd volcanicneck facies. The average amount of SiO2, K2O, Na2O and K2O/ Na2O for 92 samples of ryhyolite porphyr y and quartz porphyry are respectively 75.47%, 7.13%, 0.85% and 10.12; a nd for 3 samples of quartz feldspar porphyry are 64.76%,8.18%,0.38% and 21.53,with ratios of A/CNK ranging from 0.98 to 1.45 fo r all samples．The average value of ΣREE and δEun for 14 samples of acid rocks are 107.64 and 0.14. The characteristics of stable petr ography and lithofacies, independent occurrence and late Jurassic form ation can be recognized.Taking the selected 11 rockbodies as examples,this paper reviews and discusses briefly the geological,petrological and geochemical featu res and the characteristics of major and rare elements of this type of rocks.It is considered that those rocks are ultrapotassic peral uminous ones derived from custal sources.