組織工程是結合生命科學與工程原理的新興學門。越來越多的學者開始著手進行此方面的研究，其中又以幹細胞最吸引廣泛的注意。許多學者利用生物反應器提供循環壓力來促進幹細胞的分化，但是壓力對於幹細胞在細胞數與形狀上的影響卻很少提及。所以本文的研究方向主要是設計出一套靜水壓力式生物反應器系統，藉由探討定常壓力對於幹細胞在細胞數與形狀上的影響，來證明此系統的可行性。 實驗使用大鼠骨髓幹細胞並種植在塑膠玻片上，然後放入靜水壓力式生物反應器培養。總培養時間為3天，實驗分為系統加壓0、230、1000、5000 KPa，加壓形式為定壓，加壓時間點為培養期間的第2、3天，每天一小時。實驗結果證明以每天一小時的時間施加定常壓力230、1000、5000 KPa對於大鼠骨髓幹細胞在細胞數與形狀上並沒有顯著的影響。利用此靜水壓力式生物反應器，可以應用到更複雜的細胞測試，來探討在體外組織工程培養時壓力的影響。 Tissue engineering is a rising technology that combines the principles of engineering and life sciences. More and more investigators have begun study in this field. Among these studies, stem cells have attracted more attention. Many studies applied cyclic pressure by bioreactors to improve stem cell differentiation, but few studies have been conducted to exam the direct effects of pressure on the undifferentiated stem cells. The purpose of this thesis is to design a hydrostatic pressure bioreactor system, and ensure the system can be used in cell culture by examining the effect of constant pressure on the number and shape of growing stem cells. Rat bone marrow stem cells were seeded onto the plastic coverslip, then cultured up to 3 days in the hydrostatic pressure bioreactor constructed in house. During the period, we applied constant pressure 0 , 230, 1000 and 5000 KPa for 1 hour daily on the second and third day respectively. The results demonstrated that the rat bone marrow stem cells, when exposed to the constant pressures were not significantly influenced in cell number and shape. With this hydrostatic pressure bioreactor, more sophisticated cell tests can be done to assess the effects of pressure on the tissue engineering cell development in vitro.