This book constitutes the refereed proceedings of the 4th International Conference on Computational Social Networks, CSo Net 2015, held in Beijing, China, in August 2015.The 23 revised full papers and 3 short papers presented together with 2 extended abstracts were carefully reviewed and selected from 101 submissions and cover topics on social information diffusion; network clustering and community structure; social link prediction and recommendation; and social network structure analysis.