The kinetics of sintering of Ni(s)-NiO(s) and Fe(s)-Fe1-xO(s) powder mixts. were investigated by measurements of d.c. quantities such as resistance, emf., and current under a const. applied voltage.  Sintering of compacted pellets of the 2 powder mixts. was carried out at 1293 K in Ar at 101.325 kPa with an O partial pressure of <1 × 10-10 Pa for ∼60 h.  Different behavior of the recorded quantities was found between the 2 mixts.  The elec. resistance of the Fe(s)-Fe1-xO(s) mixt. decreased with increasing time to reach a const. value.  On the contrary, the other mixt. had a high resistance for a relevant part of the expt. and then through a transition period became low and const.  An anal. of the results in terms of resistivity and Tamman's sintering temp. of the components seems satisfactory for explaining the exptl. results.