This paper study the periodicity of international trade price of iron ore and its influence on mining business. It is demonstrated that he cycle length of iron ore’s fixed price is 29 years,the expectation price is 41. 5 $ /t,and its fluctuation range is over 45%. The inaccurate estimation of iron ore’s price is an event with a big probability if estimation is based on its three-year average price,the probability is 22 /29. Therefore,it is considered that the periodicity of mining industry should be took account in the international strategic business of iron mining and the value evaluation of mining right.