This textbook adapts the folk songs of more than 100 countries on five continents, with a focus on single part solfeggio, supplemented by a small number of double part solfeggio items, so as to meet the needs of different learning levels. Presenting the characteristics of diversified contents and different styles in content, this book is for learners of intermediate level. Therefore, in terms of use, the textbook can not only be used as a supplementary textbook for College Music Majors' solfeggio training course, but also as a sight-singing textbook for all kinds of music learners.