This book provides an introduction to plane projective geometry and affine geometry. Its main contents involve projective plane, projective transformations, transformation groups and geometry, the projective and affine theories of conics, the historic development track of geometry and so on. The book is easy both to teach and to learn, which is typical of its well-knit system, refined content and colorful pictures. The book can act as text-book for undergraduates in maths' majors as well as reference book for faculty concerned.