A laboratory model of the cyanobacterial community of the Kotel'nikovskii hot spring (Baikal Region) was developed. A step-by-step description of the algocenosis formation along both the time and temperature gradient was given. The natural and laboratory mats were compared, and the major differences in the qualitative and quantitative composition of the cyanobacterial community were revealed. The laboratory algocenosis was stratified by species composition and was characterized by rapid replacement of the dominant cyanobacterial species depending on the temperature gradient. The formation of the community structure occurred over the 18 days of the experiment. In space and time, the sequence of species emergence in the cyanobacterial mat was as follows: Mastigocladus laminosus --> Phormidium tenue --> Ph. ambiguum --> Ph. valderiae. The species composition of the laboratory mat was similar to that of the natural mat; however it was found to be less diverse.