In this study the influence of chosen detergents on the rheology of highly loaded coal-water slurries (60%wt) made up from coals of differents degree of carbonization from steam coal rank of 31.2 through 33 to coking coal rank of 35.1 according to Polish Standards were tested. In the experiments the nonionic types of chemicals - Rokwinol 60 (polyoxyethylated sorbite oleate, C₆₄H₁₂₄0₂₆), Rokanol LO18 (RO (CH₂CH₂O)_n H, where R – alkyl radical consisting of 16 to 18 carbon atoms in the carbon chain and "n" is around 18), manufactured by Chemical Factory "ROKITA " in Brzeg Dolny, Poland as well as anionic sodium lignosulphonate LSP, a by-product from cellulose production, were used. The detergents used were of a commercial purity. They were chosen taking into account the structure of molecules. Molecules of the surfactants used differ in space structure. Rokanol LO18 has a linear structure, Rokwinol 60 as a derivative of sorbitol has a branched structure whereas sodium lignosulphonate has complicated space structure. The price and accessibility of the detergents used were also considered. The test results clearly showed that the rheological properties of the CWS depend significantly on both the type of coal and the type of surfactant. The slurries prepared in this study exhibit pseudoplastic and dilatant properties. The same surfactant, depending on the type of coal, may give the CWS of different rheological behaviour. It was supposed that besides of electrostatic and dispersing forces the steric affect plays a significant role in the CWSs fluidity. The coal-water slurries, made up from all tested coals without addition of detergents, had consistency of dense mud and their viscosities were not measured..