The dynamic feature is an important aspect to deeply understand an Online Social Networks user behavior. Much of the existing work tries to investigate an Online Social Networks in a relatively static way, by collecting or studying a static snapshot dataset. However, the growth of Online Social Networks is extremely rapid. Every day new users join Online Social Networks, while existing users make new friends or end social connections, join or leave groups, and so on. Considering this dynamic can extract more inherent information than studying static data, not only revealing the situation at a certain time but also predicting some future activities. Also, studying different time intervals and time granularities would lead to more interesting findings. There are several challenges for performing dynamic analysis. One is fast data collection and timely processing, where an unbiased and efficient graph sampling algorithm can play an important role. Also, collecting dynamic data raises challenges for information storage; therefore, the temporal and spatial dependence between different data items can be utilized for better compression.