Fibrations are important tools to classify algebraic surfaces and to study moduli spaces. Fibrations over rational lines play an important role. Many fibrations with remarkable arithmetic and topological properties can be obtained from fibrations over rational lines by base changes. My lecture include two parts: (1) Classify fibrations of algebraic surfaces over rational curves, and give its applications. In particular, we hope to complete the problem proposed by Poincaré for Riccati foliation in 1891. (2) Give some ways to construct simple connected surfaces of general type.