It is important to study the moving law of oil-gas contact in oil reservoir with condensate gas cap in the interest of developing the gas cap and oil rim concurrently. Considering factors of retrograde condensation，water vapor content and rock compressibility，a new method of calculating the moving range of oil-gas contact in the oil reservoir with condensate gas cap was derived based on material balance principle and an assumption of elliptic-cone-shaped reservoir. Application case shows that the moving velocity of oil-gas contact increases after the retrograde condensation of gas cap；all the computing results of the vertical moving range of the oil-gas contact are smaller when the factors of retrograde condensation，rock compressibility or water vapor content is neglected；the influence of retrograde condensation on the vertical moving range of the oil-gas contact is larger than that from rock compressibility and water vapor content. The computing result of the new method agrees well with the one obtained by pressure gradient method.