Abstract: This paper analyses joint stress in g of scroll case concrete. Result has shown that the main factors, which influen ces the joint cracks between scroll case and surrounding concrete, steel, stress, stress of surrounding concrete and reinforcing bar. During operation to power, monitoring result has a small range under active loading. Monitoring data change mainly as the water fluctuates. Stress and deformation are within the range of allowable design. Dam operates in the normal condition.?