Professor Ito is one of the most distinguished probability theorists in the world, and in this modern, concise introduction to the subject he explains basic probabilistic concepts rigorously and yet gives at the same time an intuitive understanding of random phenomena. In the first chapter he considers finite situations, but from an advanced standpoint that enables the transition to greater generality to be achieved more easily. Chapter 2 deals with probability measures and includes a discussion of the fundamental concepts of probability theory. These concepts are formulated abstractly but without sacrificing intuition. The last chapter is devoted to infinite sums of independent real random variables. Each chapter is divided into sections that end with a set of problems with hints for solution. This textbook will be particularly valuable to students of mathematics taking courses in probability theory who need a modern introduction to the subject that yet does not allow overemphasis on abstractness to cloud the issues involved.

伊藤清（1915－2008） 日本数学家，日本学士院院士，世界级概率论大师。他因在概率论方面的奠基性工作而获1987年的沃尔夫奖，并于1998年获得京都基础科学奖，2006年获得首届高斯奖。伊藤清的工作集中于概率论，特别是随机分析领域，他被誉为“现代随机分析之父”，因他命名的理论有伊藤过程、伊藤公式和伊藤微积分。他的研究对其他学科尤其是金融数学产生了深远影响。