[Introduction]: Incidence and progression of cutaneous scars show close relationship with local mechanical force properties.Scar usually occurs at the site of high skin tensions or movements.And typical butterfly/dumbbell shape of keloid on the chest is largely determined by the direction of the mechanical forces on skin.Therefore, purpose of this paper is to explore biological effects of cellular stretch on human dermal fibroblasts, and to illustrate influences of mechanical forces on scar development and progression from a perspective of mechanobiology.[Materials and Methods]: Human dermal fibroblasts seeded onto silicon chamber were subjected to periodic stretch-relaxation stimulation for 24 hours, compared to the control under identical procedures except for stretching (n=3).Finite element analysis was performed to calculate extension rate.Dynamic images were taken at 15-min intervals under time-lapse microscope for 24 hours, followed by morphological evaluations (n=3).Microarray analysis and real-time PCR evaluations were also made to testify related gene expression profile and to quantify such expressions respectively (n=3).[Results]: Extension rate of the stretching in silicon chambers is 120%.Compared to control ones, stress-loaded fibroblasts tended to align perpendicularly to the direction of stretch; distance and velocity of cellular migration increased in stretched cells; and cell division frequency decreased in stretched fibroblasts.Various gene expressions including TGF-β were changed by cell stretch.[Discussion and conclusions]: Mechanical stretching can bring both morphological and functional changes to human dermal fibroblasts.Such biological effects are brought about by modulations involving growth factor expression, balance between matrix synthesis and degradation, and cellular-matrix interaction though cytoskeleton.Understandings of mechanically induced morphological response of fibroblasts and change of gene expression behind provide new mechanobiological perspectives for mechanism of scar development and a potential target in its treatment.