This is an English translation of the book in Japanese, published as the
volume 20 in the series of Seminar Notes from The University of Tokyo
that grew out of a course of lectures by Professor Kunihiko Kodaira in
1967. It serves as an almost self-contained introduction to the theory
of complex algebraic surfaces, including concise proofs of Gorenstein's
theorem for curves on a surface and Noether's formula for the arithmetic
genus. It also discusses the behavior of the pluri-canonical maps of
surfaces of general type as a practical application of the general
theory. The book is aimed at graduate students and also at anyone
interested in algebraic surfaces, and readers are expected to have only
a basic knowledge of complex manifolds as a prerequisite.