self-healing materials are Substances which have the ability of healing their cracks that have created on them. When material fatigue occurs, tiny cracks developing is possible. These tiny cracks can break embedded microcapsules, unbound healing agent in microcapsules and fill and fuse the cracks. The problem is that the filling of cracks with fluid from microcapsules is a one-time healing process and they are unable to heal the next cracks. The self-healing materials need body structure like arteries which heal the wounds continuously. The solution to fix the problem of microcapsules and make them disposable is using vascular networks which contain healing fluid in them. in this study vascular networks embedded in self-healing materials is considered.The vascular network have the task of carrying the healing agent to areas of interest by their containing fluid. Therefore the design of vascular structure is a very important task. When a crack forms, the pressure drops at the crack site and fluid flows from the network into the crack because of pressure differential. The objective of this study is to minimize the global flow resistance, so that, healing agents could flow inside the cracks and fix them at the shortest time. There are several parameters to improve the vascular networks. There are several effective parameter in designing vascular networks such as Channel diameter, arrangement of vascular networks, and the Number of sources of entering fluid which in this study are considered based on the constructual theory. The designated structure for this research include's one crack which is assumed as a coin in the center of the structure. The first part of the study is to describe the analytical solution of the structure in order to ensure the integrity of research and validating the results. Analysis of the structure examined in accordance with the constant pressure of the healing fluid in the network, as soon as the crack being shaped, healing fluid will come from fluid source and will be injected into the crack as much as the crack size is. By writing the mass conservation equations at each node, the pressure difference equation between the two nodes, and solving the problem using Matlab software, pressure values at the nodes was obtained. In the second part of the study, the considered structure in analytical solution and other structures for improving the function of the first structure in order to decreasing the flow resistance was considered in numerical form by the Ansys Fluent software. The results show that using two channel diameters instead of one channel diameter and also the using of three channel diameters instead of one and two channel diameters with special lay out will lead to the reduction of flow resistance of the healing fluid. Also decreasing the sources of entering fluid will improve the applicability of the solution and reducing the flow resistance. The numerical solution for Dimensionless flow resistance for the first considered structure is 123.7 which is decreased by reducing the entering fluid sources and using two and three channel diameter instead of one channel diameter and also the dimensionless flow resistance decreased. The best performance belongs to the structure with two channel diameter and 4 entering fluid sources with dimensionless flow resistance of 75.09. Keywords: Self-healing , crack, microcapsule, vascular, pressure drop, flow resistance