According to observed data of runoff and sediment load in the Yellow River from 1919 to 2012, the trend of the runoff and sediment load in the reaches upstream of Tongguan was analyzed with nonlinear statistical methods. The annual runoff and sediment discharge has shown a declining trend in the Yellow River since the mid-1980s, and the relationship between runoff and the sediment load in the upper and middle reaches of the Yellow River abruptly changed before the late 1960s and abruptly changed again in 1986. At the century scale, the runoff and sediment changes of the Yellow River were mainly influenced by climatic and other natural factors before 1960, high and low runoff and sediment loads occurred with changes in rainfall, while the runoff and sediment changes were influenced by human activities and natural factors since 1960. Though rainfall showed significant changes at different times, the runoff and sediment load decreased continuously. Over the last hundred years, the absolute value of the tendency of the annual sediment transport amount has been significantly higher than that of the annual runoff, and the absolute values of the tendency of annual runoff and the sediment transport amount in the middle reach have been significantly higher than those in the upper reach. Over the last 30 years, the runoff and sediment load were at their lowest levels in the Yellow River, and the outstanding characteristics were the continuous decrease of the runoff and sediment load, the uneven spatial distribution of the runoff and sediment load, the decrease of the sediment load mainly occurring in the middle reaches, and the decrease of runoff mainly occurring in the upper reaches. Thus, the annual distribution of the runoff and sediment load tended to be uniform, the incoming sediment coefficient tended to decrease, and the relation between runoff and sediment load tended to be strong.