Graph packing problem is one of the central problems in graph theory and combinatorial optimization. The famous Steiner tree packing problem in undirected graphs has become an well-established area. It is natural to extend this problem to digraphs. The corresponding problems in digraphs are called directed Steiner type packing problems which are highly related to some important problems in graph theory.

In this book, the author tried to collect known results on several Steiner type packing problems in digraphs, including directed Steiner tree packing problem, directed Steiner path packing problem, strong subgraph packing problem, strong arc decomposition problem, directed Steiner cycle packing problem. This book also contains some conjectures and open problems for further study. 

The author hopes this book can motivate more young researchers and graduate students to do further study in this subject, and promote the interdisciplinary research of graph theory, combinatorial optimization, theoretical computer science and communication networks.

Yuefang Sun received his PhD in Applied Mathematics from Nankai University, China in 2012. He is currently a full professor with the School of Mathematics and Statistics, Ningbo University, China. His major research interest includes graph theory, extremal combinatorics and combinatorial optimization, particularly for digraph theory. He has one book published in Springer and over 70 papers published in refereed journals.