Mr. Hsu Shih, who is well recognized through his significant and symbolic songs, ＂Anping Melody＂ and ＂Tone of the Gong,＂ is one of the most important composers of Taiwanese popular songs after WWII. Because he died when he was only 61 years old, his songs are much more well known than his name. But, as a musician, he devoted himself not only to pop song writing but to the collecting of Taiwanese folk songs. After his return to Taiwan from Japan in 1946, he travelled all over Taiwan to collect folk songs through his own effort. He also closely worked with a dancing group for tourists, ＂Ching-liu Garden,＂ in Wulai. With his hidden status, hardly anyone realized his superb contribution in his folk song collecting in the past few decades. His Symphonic Folk Songs of Taiwan premiered in 1964, had been arranged with traditional Taiwanese and Western music instruments. In this symphony, there are many Taiwanese folk songs melodies which are well assimilated in the whole work. It is the musical realization of Mr. Hsu's effort in this folk song collecting. In this paper, I'm focusing on the folk songs in Symphonic Folk Songs of Taiwan. Firstly, I study Mr. Hsu's point of view about folk songs and their collecting method. Secondly, thanks to Mr. Hsu's family who provided me with a great amount of Mr. Hsu's original materials, I am able to trace Mr. Hsu's periodical concerts, his publication of the related song books, and the series of recordings of his own folk song arrangements. The study of these activities in Mr. Hsu's career will lead us to the paths that Mr. Hsu had taken in collecting folk songs. It will also help us to discover the process of his composition of Symphonic Folk Songs of Taiwan.