GRB060115 is a long, hard GRB detected with High Energy Transient Explorer 2 (HETE-2). It presents substantial substructures in its light curve. With the spectral analysis of the whole burst and its substructures in the wide energy range of HETE-2 (2-400 keV), we find in the time history of the emission process a hard-to-soft trend first followed by a soft-to-hard evolution. This evolution is not common in GRBs, which generally exhibit only a hard-to-soft evolution. The evolution of the prompt emission of GRB060115 is discussed in this framework.