Mobile social network (MSN) is a typical social network where one or more individuals of similar interests or commonalities, conversing and connecting with one another using the mobile phone. In this paper we analyze a large-scale MSN on real mobile phone call data. The main contributions of our works can be summarized as three-fold: firstly, a large-scale MSN is constructed from the mobile phone call logs provided by a mobile phone carrier in China; secondly, based on the analysis of the common features of networks, we confirm that the MSN is a typical scale-free network and has some small-world phenomenons; lastly, different form traditional social network analysis, properties of the actors, such as gender and age, have been introduced into our analysis with some interesting finding about human behavior, for example: the middle-age people are more active than the young and old people, and the female is unexpectedly more active than the male at old age.