法性宗 Dharma-nature school. A name loosely applied after the fact to a system of study in Korea which revolved around issues of tathāgatagarbha 如來藏 and ālayavijñāna 阿頼耶識, but which approached issues from the perspective of "nature arising" rather than arising based on characteristics. Thus, a form of study established in contrast to that of Pŏpsang 法相or "dharma-characteristic." The formation of this school is usually attributed to the influence of Wŏnhyo 元曉. 

The sects, e. g. 華嚴宗, 天台宗, 眞言宗 Huayan, Tiantai, Shingon, which hold that all things proceed from the bhūtatathatā, i. e. the dharmakāya, and that all phenomena are of the same essence as the noumenon.

華嚴宗五祖宗密所判大乘三宗之一。又稱性宗。此宗認為，一切眾生之心並非由於斷惑而得清淨，實乃本來清淨者，故眾生之心即為法性。宗密判大乘為法相、破相、法性等三宗，法相宗，指以五位百法等建立法相之唯識宗；破相宗，指以四句百非破一切法相之三論宗。依華嚴五教判而言，前者相當於相始教，後者相當於空始教。相對於此，法性宗則相當於終、頓、圓等三大乘，亦包括華嚴、天台等宗。宗密又主張法性宗較法相、破相二宗為優。
　永明延壽於宗鏡錄卷五謂，「法相」多說事相，如法相宗，離第八阿賴耶識即無眼、耳等諸識；「法性」唯說理性，如法性宗，離如來藏即無八識。一般以主張真如（法性或佛性）為世界本源者為法性宗，以分析法相，論證萬法唯識者為法相宗，多稱大乘中觀學派及中國之三論宗為法性宗，亦有將華嚴宗、天台宗、三論宗、密宗等稱為法性宗者。〔圓覺經略疏卷上之一〕（參閱「性相二宗」3231）

謂此宗說依真起妄，蓋真如不變，不礙隨緣，如云：法身流轉五道，如來藏受苦樂等。若悟妄即真，如云：知妄本自真，見佛即清淨等，是名法性宗。（五道者，天道、人道、餓鬼道、畜生道、地獄道也。）