Nowadays, cellular structures are widely used in various industries such as aerospace industry, automobile industry, vibration absorbers, medical industry, and thermal insulators due to their unique features such as minimal weight, high strength, high absorption capacity, and adjustable mechanical properties. Perhaps the most important feature of cellular structures that makes them suitable for structural applications is the high strength-to-weight ratio of theme. This feature allows the production of lightweight structures and reduces the required raw materials, energy, and contaminants appropriate to them. With the development of additive manufacturing (AM) technology in recent years, today, many of these structures are built in this way and are rapidly developing. The use of AM methods allows control over the distribution of material in the structure, while this is not possible in conventional methods. In this thesis, the main focus is on the design and construction of metallic structures by selective laser melting (SLM) process and investigation of lightweight structures with a high strength to weight ratio. To achieve this goal, mechanical properties of eight metallic structures with different topologies (BCC, BCC-Z, FCC, FCC-Z, Gyroid P, Rhombic, Diamond, and Kelvin) under pressure test were investigated. The results highlighted that the advanced cell structure Gyroid P had the highest strength to weight ratio compared to other seven structures. The energy absorption of structures relative to the weight has been investigated too, and the structure Gyroid P for this application has been shown to be well-suited. In addition to the experiments, the simulation of metallic samples was carried out with the elastic-plastic behavior, and the effects of the material and the influence of geometry on the behavior of these structures were evaluated. The results of the analysis showed a great influence of the bulk material properties and geometrical details on the mechanical properties of the cellular structure. Therefore, with the aid of some adjustments, the simulation and experimental results showed a good coherence in the elastic-plastic region, so that simulation can be generalized for structures with density and shape of different cells. Keywords: cellular structures, additive manufacturing, selective laser melting, unit cell, strength to weight ratio, 316L stainless steel