We have performed laser-excited ultrahigh-resolution photoemission spectroscopy of Y(Ni 1− x Pt x ) 2 B 2 C (x=0.0, 0.2) and numerical simulation using s, anisotropic s and even s+g symmetry to study the superconducting gap anisotropy in borocarbide supercodnuctors. We observed the reduction of gap anisotropy in the x=0.2 sample in comparison to the x=0.0 sample, confirming the anisotropic s-wave gap. We also found that the spectrum of x=0.0 at 3.5K cannot be fitted well with the s+g-wave symmetry, implying that the s+g symmetry is too simple to describe over all supercodncuting gap electronic structure of borocarbides.