Abstract:  
The subject of this research is the method of fuzzy linear regression as a tool of sociological modelling of a number of demographic indicators. The work applies the method of fuzzy linear regression based on the fuzzy triangle numbers. The object of this research is the various elements of demographic behavior of population that is implemented in the article for analyzing and forecasting the matrimonial behavior and birth rate coefficient in the Altai Region. The fuzzy linear regression is considered as alternative to the standard statistical linear regression in case of the brief time series and the unknown law of distribution. With the help of the framed algorithm based on the simplex method, are detected the coefficients of fuzzy linear regression for the time series of demographic indicators of Altai Region for the period of 2000-2016 that characterize the trends in dynamics of demographic processes. The method of fuzzy linear regression was originally proposed in 1980’s, but has not been largely implemented in scientific research, as well as never used in the socio-demographic research. The author makes a conclusion on the prospects of such method for the sociological and demographic studies.