In the space of just a few years, nanotechnology has become a topical subject not only in academia, but also in the daily lives of people. In order to investigate the properties of natural nanoparticles (NNPs) and to obtain a better understanding of their environmental behaviour and impacts from a new perspective, transmission electron microscope (TEM), zeta potential analysis and time-resolved dynamic light scattering (DLS) analysis were used to examine the main properties and aggregation kinetics of NNPs extracted from Chinese soils added to various concentrations of the electrolytes NaCl, CaCl2 and LaCl3. The NNPs that were less than 100 nm remained stable for 100 days. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) model partially revealed the aggregation behaviour of NNPs, in which ionic strength, composition and size may play important roles. The influence of hematite and natural organic matter (NOM) was demonstrated by aggregation kinetics and critical coagulation concentrations (CCC). The size of NNPs could also change the maximum total potential energy of interactions in the systems (VT(h)). These factors make the aggregation of NNPs in electrolytes different from that of soil colloids and influence the environmental behaviour of NNPs.