The observed river runoff is resulted from the nature and human activities. In order to analyze the natural runoff on the upstream of the Majiahe River during the period of 1956-2000, the observed data about the water consumption and diversion on the controlled catchment of the Nanle Gauging Station are calibrated. Analysis of the precipitation, observed discharge and calibrated discharge shows that natural changes of discharge is sensitive to the climate changes, and human activities have became more important factors than physical factors in affecting the discharge change. The rainfall-runoff relationship in two different durations indicate that the runoffs in the recent 20 years are larger than that during the period of 1956-1979, which reflects an obvious change of the runoff-yield and flow concentration mechanism.