The effects of the properties of substrates and tackifier on the shear creep of SIS-based HMPSAs were investigated. The holding power (t(b)) and shear adhesion failure temperature (SAFT) were measured. The relationship between the complex viscosity and the holding power was examined. The holding power and SAFT values of the triblock SIS blends were higher than those of the diblock-containing SIS blends, perhaps because blends using triblock SIS have higher crossover temperature and complex viscosity than those using diblock-containing SIS. Higher levels of aromatic resin-modified aliphatic tackifier and rosin ester were found to decrease the holding power of the HMPSAs. This maybe due to the fact that rosin ester and aromatic-modified aliphatic resin are compatible with both the ends and midblocks of SIS. (c) 2006 Wiley Periodicals, Inc.