Temperature and major species concentration profiles are obtained in H-2/N-2 versus air-opposed flow diffusion flames of various fuel jet dilutions and strain rates. Three fuel jet compositions are examined: mole fractions of 21% H-2 and 79% N-2, an equimolar mixture of H-2 and N-2, and undiluted H-2. A Raman imaging system, capable of providing time-averaged linewise measurements of high precision (2%) and high spatial resolution (160 mu m), is used to obtain the scalar measurements. Laser Doppler velocimetry is used to measure the oxidizer-side axial velocity gradient, K, ranging up to 3800 s(-1). Mixture fraction and scalar dissipation rate profiles are derived from the major species concentration and temperature profiles and clearly show effects of differential diffusion, with deviations among the three elemental species mixture fraction profiles for all three fuel jet conditions examined. Flame thickness is experimentally shown to vary linearly with K--1/2. Differences in boundary conditions allow only a qualitative comparison between measured peak temperatures and others＇ numerical results. However, the comparison generally provides good agreement, especially for the highly diluted fuel jet case (+/-40 K), though for undiluted fuel jet flames at low values of K the experimental data are consistently higher (90 to 280 K) than numerical predictions. Also, for the low K undiluted fuel jet flames, the scalar dissipation rate versus mixture fraction profiles are nonmonotonic near the stoichiometric mixture fraction and have values there that are over an order of magnitude less than their more diluted counterparts, due to the influence of fuel jet dilution upon the relative positions of the stoichiometric location and the stagnation plane.