Tissue engineering is a kind of interdisciplinary study based on applying the principles of both engineering and life sciences for the development of biological substitutes and try to restore, maintain or improve the tissue function. Bioreactors are used in tissue engineering study as very important devices. Currently, the research on the improvement of bioreactors are mainly stressed on the biomechanics, three-dimensional culture, mass transport, the culture environment condition (pH, the oxygen tension, etc.) and physics factors such as electric filed, magnetic field, stress field,etc. The discussion about bioreactors in this paper mainly probe into the biomechanics problems of Bioreactors in tissue engineering.