During 20th century, the extensive and standing contact and communication were done between the Eastern and Western cultures in China, some of Chinese musicians applied themselves to music production, and others completely flung into collection, record, coordination and study on the abundant treasures of the Chinese traditional music. The activities as above succeed not only suitably to the collection of folk songs, i.e. "Caifeng" for about three thousands years, but also are deeply affected continuously by new cultural tideway and some other "new theories" in the 20th century. Therefore such activities hereinafter are referred as ethnomusicological field works. This article targets to the field works from 1900 to 1966 by means of the combination of the chronicle method with analysis of individual cases for study. The article is divided into two parts along with seven chapters wherein the background, theory, methods achievements, experience as well as questionnaires of the ethnomusicological field works that are surveyed, analyzed and studied based on records by non-musicians, foreigners and Chinese musicians before 1949, and by Chinese musicians in Mainland China from 1949 to 1966 in order to try hard to primarily clear up the pulse of subject construction of the Chinese ethnomusicology. The idea to be referred for the stability and deve lopment of the Chinese ethnomusicology is provided herein. The object of this article is to show that the experience of the ethnomusicological field works are included in background of change in modern Chinese history and to know the relation of construction of the Chinese ethnomusicology to the development of modern China as we as the relation of the same to the folk society. It is seriously considered that folk music in the Northwest of Shangxi excavated and settled by musicians of Yan 'an in the first half of 20th century and a series of investigation or field works on the traditional music are significant foundation for the growth of the Chinese ethnomusicology. But exploiter and foreign scholars in the fields of ballad, social ethnology in the earlier time should be respected sincerely. It is no doubt that the field works in 20 century have been set up a very stable foundation for the ethnomusicology in China.
