The thickest loess formations, more than 100 m, are located in China and Tajikistan. Climatic and geographical factors became the basis for development of the atmospheric aerosol accumulation model in Tajikistan. Dust originated from huge deserts of the Central Asia is transported by western winds to valleys of Tajikistan where it drops out forming loess sediments. According to calculations the average thickness of dust sediments is 0,2 mm/year. This value agrees to the records obtained from loess section of the Early Holocene. Comparison of the modelling results and the real data from loess sections proves good correlation between these two independent approaches. It is one of the arguments supporting the concept of loess formation due to atmospheric aerosol.