The distribution of reservoir properties is commonly subjected to normal probability. There are two disadvantages in the traditional method to study reservoir properties distribution by logarithm normal probability sheet or normal probability sheet: one is, when normal probability sheet is unavailable the method will not work; the other is, reading by handcraft leads to poor accuracy. In using of normal distribution function, this paper puts forward a new method to study the distribution of rock properties by using the Microsoft Office Excel software on computer. The study in case proves that the new method is convenient and the result is credible.