The thermogravimetric analysis (TGA) and electron paramagnetic resonance (EPR) studies of powder and single crystals of bis(acesulfamato)tetraaquazinc(II), Zn(acs)(2)(H(2)O)(4), a novel coordination compound, are carried out. Previously synthesized bis(acesulfamato) tetraaquamanganese(II), Mn(acs)(2)(H(2)O)(4), is included into the host in trace amount as a paramagnetic probe for EPR analysis. Single crystal EPR spectra at room temperature are resolved and discussed. Low temperature EPR spectra down to 90 K do not show remarkable change. At higher temperatures, however, the TGA and EPR spectra show changes around 335 K and 395 K; the causes and the mechanisms of changes are discussed. (C) 2011 Elsevier B.V. All rights reserved.