The purpose for this research can be divided into two parts. Firstly, the study of the near-UV LED excitable yellow-emitting carbonitride phosphor. Secondly, the study of the blue LED excitable green, yellow, orange, and red-emitting sulfide phosphor, and their potential applications on white LED devices. Chapter 1 introduces the research background and current situation of nitrides and sulfides, and then elaborates the motivations and goals of this thesis, and by the literature review of focusing on the fundamentals of phosphor, concentration quenching of activators, mechanism of energy transfer and discussions of different types of phosphors. Chapter 2 introduces the synthesis methods and characterizations of the four types of nitride and sulfide phosphors, viz., Y2(CN2)3:Ce3+, Y2AEF4S2:Ce3+ (AE=Ca, Sr), α-YFS:Ce3+, and β-YFS:Ce3+. Chapter 3 dipicts the crystal structure and spectroscopic properties of the yellow-emitting Y2(CN2)3:Ce3+ phosphor and its application on near-UV LED excitable white light device. Chapter 4 discusses that the crystal structure and spectroscopic properties of the Y2AEF4S2:Ce3+ (AE = Ca, Sr), α-YFS:Ce3+, and β-YFS:Ce3+ phosphors and their applications on blue LED excitable white light device. Chapter 5 summarizes the properties of the carbonitride and fluorosulfide phosphors and discusses the future work.