We have investigated the influence of sample width on the transport properties in YBCO thin film using 10, 120, and 1200 μm-wide bridges formed in a same c-axis oriented YBCO film deposited on a SrTiO 3 substrate. We measured I-V characteristics of the bridges at various temperature, T, and magnetic field, B, perpendicular to the film surface. It has been found that the so called glass-liquid transition field, B G L , reduces as the sample width becomes narrower, while the critical temperature, T c , and critical current density, J c , in the glass region (B<B G L ) are almost independent of the width of the bridges. The good agreement of T c and J c in three bridges indicates high uniformity of the bridges and that the reduction of B G L does not come from the degradation of the film. The measured width dependence of B G L can be scaled with a constant critical index as can be predicted by the percolation model at all measured temperature region from 70 to 85 K. The influence of sample width on J c has also been discussed based on the scaling analysis.