To obtain a syndiotactic polystyrene type support for the photographic sensitive material keeping its intrinsic superior property and transparent and superior in surface flatness and small in curling tendency by controlling the difference of refractive indices in the thickness direction between the surface and the reverse surface of the support.

The nonstretched amorphous support comprising the syndiotactic polystyrene is biannually stretched and oriented and set by heating and the difference of refractive indices in the thickness direction between the surface and reverse surface is controlled to ≤4×10-3, preferably, ≤2×10-3, and especially, infinitesimally nearer to zero, and if its difference is over 4×10-3, the support curls with the side higher in the refractive index inside, and a flat support cannot be obtained.