Temperature and species mole fraction profiles were determined in atmospheric-pressure, premixed, laminar, flat flames of I, 1-C 2,H4,CI2, and CH4, under fuel-rich conditions at different CI/H ratios. Samples were withdrawn from within the flame using a heated microprobe followed by gas analysis by on-line capillary gas chromatography-mass spectrometry (GC/MS). The mole fraction profiles were determined for all the reactants and for CO,CO2, HCI, H2O, H2,C2H6,C2H4, C 2H2,CH3CIC2H3CI, CH 2CCI2,CH3CHCICH3,CH 2CCICHCH2,C4H4,C4H 2,C6H6 (benzene), and C10, H 8 (napthalene). The roleofthesespecies,in view ofthecurrent ideasofthe mechanismofcombustion of 1.7-DCE isdiscussed and compared to earlier measurements made in I,2-C2H4CI2 flames. © 1995 OPA (Overseas Publishers Association) Amsterdam B.V. Published under license by Gordon and Breach Science Publishers SA Printed in Malaysia.