Atmospheric dust samples were collected at monthly or seasonal time intervals at six sites on the Chinese Loess Plateau during 1995--1996 and 2000. The dusts are mainly composed of mineral grains in addition to a considerable amount of organic material, especially in the case of the dusts deposited in summer. The magnetic susceptibility of these modern dusts is generally higher than that of glacial loess, and in addition they show clear seasonal variations with maximum values in the summer dust and minimum values in the winter dust. Assuming that pollution effects on modern dust can be excluded, this implies that the high susceptibility values of Quaternary paleosols may arise either from the direct effect of climate on the baseline susceptibility of the raw dust or from further enhancement by post-depositional pedogenesis. The pattern of seasonal dust flux shows that most of the total annual dust deposition is generated by continuous deposition throughout the year rather than by dust storms in specific seasons; however, the flux does exhibit seasonal variability with highest flux occurring in spring or early summer, especially in the northern Loess Plateau. The grain-size distribution of modern dust shows a positive-skewed asymmetrical pattern that is analogous to Quaternary loess. Seasonal variations in dust grain size are characterized by coarsening in spring and summer and by fining in autumn and winter. At a specific site the dust grain-size strongly depends on height above the local ground surface and decreases nonlinearly with increasing height. On the basis of vertical profiles, spatial trends and the seasonal variability of dust flux and grain size, we infer that modern dust, and thus Quaternary loess, is mostly transported at a low level of the atmosphere throughout the year with intensified dust deposition in spring and early summer.