Students and teachers call this book the main psychological book in the country, because a good dictionary is the basis for both theoretical research and practical work. This book has stood the test of time. Here is the latest edition of the famous dictionary. The new fourth expanded edition is the product of a deep revision of the “Big Psychological Dictionary” (2003), which, in turn, was based on the previous two editions of 1983 and 1996. Its main differences can be summarized as follows. First of all, about 400 new articles were added to the dictionary, thereby the total number of articles exceeded 2000. Many articles from the previous edition were revised or completely replaced by articles with new content, in some cases it was necessary to make additions that were already traditional for our edition. The authors of a number of articles sought to present information on the results of scientific research conducted at the very end of the last century and at the beginning of the 21st century. Thus, the dictionary began to more fully reflect the situation in modern domestic and world psychology.