The human mesenchymal stem cells can differentiate into cardiomyocytes, osteoblasts, chondroblasts, adipocytes, endothelial, hepatocyte and neuron cells, when hMSCs are exposed to certain physical and chemical stimulants. It is hoped that the differentiation of hMSCs into certain cell types in certain in-vitro conditions can provide for treatment of the certain disease and pathologic situation. The suitable cell culture conditions, which are needed for differentiation of hM5Cs into osteoblast, chondroblasts and adipocyte cells, are known. However, these cells do not reach to terminal differentiation but they can differentiate only into osteoblast, chondroblast and adipocyte-like cells. It is thought that these cells are precursor cells. Moreover, hMSCs can differentiate into different types of cells under the mechanical stress (mechanical stretching, pressure, shear stress) as the physical stimulus. However, it is not clear whether mechanical stretching provides for the hM3Cs to reach terminal differentiation or not. It was found that the tension on the cytoskeleton and/or the tension in the junctions between the cells caused hMSCs to choose the certain cells type differentiation way. Increasing acknowledge about parameters of the tension in the cells and/or between the cells can provide that these parameters can be used to follow the progression of pathologic situation and the diagnosis of some cardiac, bone, joint and muscle tissue diseases. Nowadays, there are several projects about finding mechanical properties of the soft and hard tissues in the biomedical fields To show properly working of in-vitro mechanical, 6 hours, 5% and 1 Hz of mechanical stress was applied for hMSCs. factin florescence stainin was done to see stress fibers. Stress fibers were observed after mechanical stress. In the present study, in-vitro mechanical stretching system (iMecS) was developed with experimental applications.