The SRTC, according to its mission in promoting the statistical knowledge of society, has put the writing and publication of specialized books and magazines on its agenda. The authorship of the present book is one of the measures that have been taken by SRTC to implement this policy, and it is hoped that it will be useful for researchers and students in the field of statistics and related fields. The topic of "time series" is one of the statistical topics that has many applications in various sciences. The results of using time series models are usually very attention-grabbing and the predictions obtained in this way are relatively accurate. For this reason, these results can be used extensively in macro-planning. Considering the existence of a lot of time series data in the country's statistical system, it is obvious that time series modeling methods can have a dramatic and major impact on the production of statistical knowledge in general and wide applications in the country's statistical system in particular. At present, in the scientific community of the country, the lack or shortage of books related to this topic is quite evident. The publication of the present book can bridge the existing gap to a considerable extent, and especially in terms of its key feature as a textbook, it can be effective in the publication and dissemination of statistical science centered on "time series". Despite the fact that many books on time series have been published in English, the existing Persian books have been less able to meet the satisfaction and needs of the audience. However, it seems that the book "Introduction to Time Series Analysis with S-PLUS Software", which is based on the experience of several years of teaching in universities, was written by Dr. Mojtaba Khazaei and edited by Mr. Farshid Khanzadeh with great care, can meet the needs of the audience.