The first brief mention of Fasheng appears as an appendix to the biography of Dharmakṣema 曇無讖 in Huijiaoʼs 慧皎 (497–554) Gaoseng zhuan 高僧傳: "Around the same time in Gaochang there was a monk Fasheng; he also traveled to foreign countries and composed a report, which consists of about four volumes." 「時高昌復有沙門法盛。亦經往外國立傳。凡有四卷。」T 2059.50.337b1–3. Ochiai, examining various evidence, identifies Fashengʼs travel record with the Liguo zhuan 歷國傳 listed in the Daishōjō ritsuron shoki mokuroku 大小乘經律論疏記目錄 preserved in the Hōkongōin 法金剛院, Kyoto. This would mean that this text was also brought to Japan and was extant as late as the 12th century. Unfortunately, there is no record of its present existence.

A more detailed biography about Fasheng is found in the Mingseng zhuan chao 名僧傳抄 compiled by Zongsheng 宗性 (1102–1192)3 :

Fashengʼs original family name was Li, a man from Long-xi but who lived in Gaochang. He became a monk at the age of nine. He diligently read and recited (Buddhist texts). Every day (he said to himself); "Although I have understood the three cores (referring to 佛法僧, or 三歸依、or 三藏？), I am not yet firmly established [in Buddhism]. The five aggregates arise and become extinct. Everything meets and separates, all are because of foolish attachment. If I could not cut off the three kinds of poison, what shall I seek after in studying?" When he became 19 years old, he met a monk, Zhimeng 智猛, who had just come back from (his travel in) foreign countries and related many miraculous experiences. Inspired by his stories Fasheng became resolved [to travel abroad]. He took leave from his parents, and leading his spiritual teacher and 29 people, he made pilgrimage far to India. He traveled through many countries, widely visited holy sites (connecting to the Buddha) and various auspicious places, and there he paid homage and performed services with actions by three means, namely, by body, words and heart. In the northeast of Udyāna he saw a statue of Maitreya made of gośīrṣacandana wood. Its height was 8 xun 尋. 1 xun corresponds to 1 zhang 丈 of our country. 480 years after Buddhaʼs nirvana there was an arhat named *Harinanda. In order to save people he ascended to the Tuṣita heaven and portrayed [Maitreya] Buddhaʼs true figure. That is this statue. It always emitted rays of light; four kinds of musicians played music in four seasons. People from a far all finally because of the image repented [their sins], and when they made a vow limitlessly, they attained the first realization of the right path in ten and several years. Monks and lay people from all directions, 500 altogether, made a vow to sacrifice their bodies. If you see [the image of this] Maitreya, the wish can be fulfilled. Fragrant smoke turns toward right and immediately all smoke gathers together to make a cover and circles three times rightwards, and then it gradually disappears etc. 法盛本姓李。壟西人。寓于高昌。九歲出家。勤精讀誦。每日、吾4 三堅未樹。五衆生滅。合會有離。皆由癡愛。若不斷三毒。何求勉脫。年造十九。遇沙門智猛。從外國還。述諸神迹。因有志焉。辭二親。率師友。與二十九人。遠詣天竺。經歷諸國。尋覓遺靈。及諸應瑞。禮拜供養。以申三業。□憂長國東北。見牛頭栴檀彌勒像。身高八尋。一尋是此國一丈也。佛滅度後四百八十年中。有羅漢名可利難陀5 "呵利難陀羅漢, 譯曰呵利者師子難陀者歡喜。" 6 。爲濟人故。舛（昇）兜率天。寫佛眞形。印（卽?）此像也。常放光明。四衆伎樂四時咲樂。遠人皆卒從像悔過。願無不剋。得初道果。歲有十數。盛與諸方道俗五百人。願求捨身。必見彌勒。此願可諧。香姻7 右旋。須臾衆烟合成一盖。右轉三匝。漸漸消盡云々。(Xuzang 續藏 二乙・七套・1・13・左, 新纂『大日本續藏經』版77卷358–359).

His travel record, the Li-guo-zhuan 歷國傳 is unfortunately lost; however, in the Fan-fan-yu (翻梵語, T 2130, probably compiled by Baochang 寶唱 we can find fifty-eight Sanskrit words cited from the Liguo zhuan 歷國傳. Ochiai rearranged these citations according to the volume number of the Liguo zhuan, so that we can vaguely imagine through which route Fasheng traveled in India.At the end of his travel he most probably visited Sri Lanka too, since the name of three principal monasteries in Anurādhapura, the Abhayagirivihāra, the Mahāvihāra and the Jetavanavihāra are found. Fasheng may also have returned to China by sea from Sri Lanka, as did his predecessor, Faxian. 〔梁高僧傳, 開元釋教錄, 隋書經籍志〕