The dispersion characteristics of hydrogen leaking through a small hole from a high-pressure reservoir are investigated numerically and experimentally to provide a guideline in determining the safety distances for hydrogen stations. The studies were carried out for the leaking holes with diameters of 0.5, 0.7 and 1.0mm and for the release pressures at 100, 200, 300 and 400 bar. Because Froude numbers in these realistic hydrogen leaking conditions are very large, it is reasonable to employ a 2-dimensional axisymmetric approach in the numerical simulations as well as in hydrogen samplings.