Prior investigation suggested that a new cluster forms at hundreds of degrees above the liquidus in Bi-Sb10 alloy and this new cluster is irreversible after subsequent cooling. The aim of this work was to explore the effect of the unknown cluster on the solidification kinetics of Bi-Sb10 alloy by using the Newton thermal analysis (NTA) method, complemented with information provided by microstructural characterization. The hypothesis about the formation of plentiful clusters with similar structure, owing to liquid structural transition (LST), was proposed to rationalize the great change of solidification process and microstructure. (C) 2007 Elsevier B.V. All rights reserved.