Various phenomena governed by power law distributions are common in nature and in society, thus their study has broad and far-reaching significance. This paper focuses on a kind of power law phenomenon originating from human behaviors, for instance, popular web page or blog distribution and so on. It is pointed out that human behaviors are rational and selfinterested. On the basis of this, we established a model and found that variables of this kind obeyed a new distribution which was named as the Wei distribution rather than Zipf distribution. Based on Wei distribution, Yule distribution was generated through changing the restrictions. Moreover, in the paper, we describe the meaning of Yule distribution and set up a new distribution which would characterize the reallife conditions more faithfully. It is illustrated further that the human behavior theory could be applied generally to explaining this kind of power law phenomenon and the model could be expanded easily. Besides, we put forward a function to compare different kinds of distributions. This paper supports the reductionism in power law phenomena, which means that simple human behaviors lead power law to be universal.