This experimental study was performed to investigate directly the local flame properties of turbulent propagating flames at the same weak turbulence condition, in order to clarify basically the influence of the addition of dilution gas to hydrogen mixtures on its local burning velocity. The mixtures having nearly the same laminar burning velocity with different dilution gas types and equivalence ratios were prepared. A two-dimensional sequential laser tomography technique was used to obtain the relationship between the flame shape and the flame displacement in a constant-volume vessel. The local flame displacement velocity S_F, curvature and stretch of turbulent flames were quantitatively measured as some of the key parameters of local flame properties on turbulent flames. Additionally, the Markstein number Ma was obtained from outwardly propagating spherical laminar flames, in order to examine the effect of positive stretch on burning velocity. It was found that the trends of the mean values of measured S_F with respect to dilution gas types and equivalence ratios corresponded well its turbulent burning velocity. The trend of the obtained Ma could explain the S_F of turbulent flames only qualitatively. The local burning velocity at the part of turbulent flames with positive stretch and curvature due to the Ma, S_Lt , attempted to be estimated quantitatively. As a result, a quantitative relationship between the estimated S_Lt and the S_F at positive stretch and curvature of turbulent flames could be observed only for mixtures with Le > 1 or Ma > 0, regardless of dilution gas types.