Advancement of technology and consequently decreasing size of the advanced systems have set a focus on energy consumption and energy loss exclusively in small scale. Therefore, heat management is a critical challenge when it comes to design of processes and systems. Vessels as the most common method of cooling in engineering systems have a significant impact on systems efficiency, so optimization could increase this impact. Hence, in this project optimized structure of cooling vessels in a cubic block was investigated, with a constant heat flux on outside walls and a constant amount of flowing fluid through the vessels. Volume ratio of the vessels to the total volume of the cube is considered fixed in order to investigate the impact of the number, arrangement, double scaling and change in cross section of the vessels on the heat and mechanical performance of the block. As a result, using indicators such as temperature reduction and maximum tension, the optimized structure is proposed. The result showed that increasing the number of vessels firstly reduces the temperature and maximum tension, then by continuing this trend increases both temperature and maximum tension. As the optimized mode, installing 8 vessels, when the temperature and maximum tension decreased by 9.8% and 67.5% respectively, is proposed; in addition, arrangement investigation of the vessels showed that approaching the vessels to the edge of the block more than a certain distance can diminish the effect of mentioned optimized mode. Accordingly, symmetric arrangement of 8 vessels (10 mm away from the edge and 15 mm away from the axis) decreasing the temperature and maximum tension by 10.2% and 75.2% respectively, is proposed as the optimized arrangement. There is something to be said that double scaling of the vessels in the investigated situations had negative result on indicators and changing in the cross section shape of the vessels showed that the square shape can upgrade the decreasing effect to 14.4% and 82.4%. Keywords: Cooling vasculature, Optimization, Mechanical strength, Thermal stress, Constant heat fluxt, Heat transfer