Adaptive regional total electron content space distribution model, based on the data of the IGS (International GPS Service for Geophysics) international network of GPS-stations is proposed in the article. The method of the spherical harmonic analysis with the selection of the spectrum of approximating harmonic with the greatest contribution was applied at creation of the model. The method essence consists in a such spherical harmonics series spectrum selection when the harmonics, with orthogonal projection exceeding an input data errors level appropriate number of times, are used in an approximating function. The comparative estimation of results obtained by the least squares process and throug offered method has executed. The usage of the least squares process when solving the problem of the spherical harmonics analysis at reconstructing the space distribution of the total electronic contents because of the poor conditionality of normal equations system, results in considerable errors of approximating strongly dependent on selected the length of series. The selection of the spherical harmonics series spectrum with the greatest contribution allows to regularize the normal equations system solution and to increase its accuracy and stability. The model can be used to increase the accuracy of detecting satellite radionavigation system users in a relative navigation mode, at ionospheric monitoring etc.