遼寧的朝陽北塔為當地著名地標，遼代在隋唐基礎上修葺而成，外觀方形中空十三級密檐式磚塔，塔身四面刻有金剛界四佛浮雕。在1988年維修清理朝陽北塔的塔頂時發現遼代所埋藏舍利天宮，隨後文物有關當局加以考古挖掘，出土一批珍貴的遼代佛教文物。天宮出土一座木胎銀棺，木質的部分因為佛塔曾經受雷擊，天宮中所瘞埋的有機物質皆化為灰燼，但木胎外四面所鏨刻的造像銀片卻保存下來，該銀棺前檔銀片為彌勒佛說法圖，後檔為天王圖，兩側銀片右幫為涅槃圖、左幫為三身圖。關於三身佛圖呈現法、報、化三身，是目前中土所發現遼代最早的三身圖彌足珍貴。關於三身佛的排列方式也相當特別，與今日三身佛中以法身佛為主尊，主尊佛左側報身佛，主尊佛右側化身佛有別。銀棺三身佛的主尊為報身佛，主尊左側為法身佛，主尊佛右側為化身佛，而主尊報身佛呈現法界人中像，法身佛呈現出金剛界大日如來貌，化身佛為常見的佛像樣貌。銀棺上的三身佛為何有如此安排？為何呈現如此造像表現？造像所呈現的佛教教化義理思想為何？經由本文探討後得知，隋代天台宗判教將佛身分為法報化三身，使得此說在唐代已有流傳，但有些佛門宗派與祖師並不認同此說。宋遼金時期天台宗判教三身佛之說更為普及，開始出現相關造像，銀棺三身佛的出現便是此時代思潮下產物。銀棺主尊報身佛，傳遞出遼代佛教是以華嚴教法為主，對於密法也是相當器重，使得華嚴與密法在判教思想上產生融合現象，將此二教皆視為圓教之法，將華嚴教主視為報身佛，大日如來視為法身佛，以華嚴教法為核心之下三身佛才會呈現如此特殊安排。

Chaoyang North Stupa (Chaoyang beita 朝陽北塔) is a famous landmark in Liaoning 遼寧, which was renovated upon the pre-existing Tang stupa during the Liao 遼 Dynasty. The upper part is a 13-layered hallow square-shaped brick structure while the lower brick structure is decorated with the four Vajrayana Buddhas in low relief. During a thorough checking and repairment project in 1988, 2 Shakyamuni's relics were found in the highest two levels, the "palace in the sky" (tiangong 天宮), where a huge amount of rare Liao Dynasty Buddhist artifacts were excavated subsequently. Among all the exquisite sacred objects, there was a wooden miniature sarcophagus decorated with silver plates. However, after being struck by a thunder, all the organic matters in the tiangong were burnt to ash, including the wooden part of the sarcophagus. The four surviving silver plates are Preaching Maitreya Buddha on the front, a heavenly King on the rear, Shakyamuni Buddha's Nirvana, and the Trikaya Buddhas (sanshenfo 三身佛) on either side. This earliest known Liao representation of the Trikaya Buddhas was different from most other ones while the Dharmakaya (fashen 法身) as the central figure, Sambhogakaya (baoshen 報身)on the proper left side, and Nirmanakaya (yingshen 應身) on the proper right side. In the Chaoyang North Stupa, the Trikaya Buddhas are presented with Sambhogakaya as the central Buddha, Dharmakaya on the proper left side, and Nirmanakaya on the proper right side. Furthermore, the Sambhogakaya is represented by the Buddha who embodies all sentient beings within (fajierenzhong xiang 法界人中像), the Dharmakaya is represented as the Vajrayanic Vairocana Buddha (Darirulai 大日如來), and the Nirmanakaya is the most commonly seen generic Buddha. What is the logic behind this arrangement? Why are they presented as such? What is the doctrinal element behind this representation? Research showed that Tiantai school established the Trikaya system during the Sui Dynasty yet was not accepted across the board by the Tang Dynasty. Several centuries later, images of the Trikaya started to appear after the Song Dynasty which led to this particular Trikaya image on the silver plates found in Chaoyang North Stupa. Designating Sambhogakaya as the central Buddha signifies that during the Liao Dynasty, Huayan Buddhism was the mainstream and Tantric Buddhism was not uncommon. Under this specific consideration that the synthesis of Huayan and Tantric as the complete teaching, the Buddha who embodies all sentient beings was chosen to be the Sambhogakaya and Vairocana Buddha as the Dharmakaya.