Dislocations commonly form microstructures in crystalline materials during mechanical deformation. Dislocation structures have also been characterized to describe interfaces including grain boundaries and interphase boundaries. Formation and evolution of dislocation structures play crucial roles in determining the mechanical, plastic, and irradiation properties of the materials. The long-range elastic interaction and various short-range interactions of dislocations, stochastic effects of dislocations, and interactions of dislocations with other crystalline defects are essential for the energetics and dynamics of these dislocation ensembles. Developments have been made to understand dislocation structures and properties, incorporate more detailed local dislocation mechanisms in the continuum level plasticity modeling, and simulate large-scale systems and/or for long-time using discrete dislocation dynamics and atomistic models. Recent experimental results have also enabled in-depth understanding of dislocation-related mechanical and plastic properties of materials. These achievements provide bases for the further development of novel materials with specialized functions. The recent developments of modeling, simulation, and experimental approaches and new findings in this research area will be discussed in this symposium.