Shrinkage induced tensile force was observed in a 264m long reinforced concrete struts through field monitoring during a foundation excavation in Shanghai, China. In the construction period, shrinkage occurring in latter cast concrete induces a tensile force to the former part of long Reinforced Concrete strut. Inclinometer installed in retaining wall also shows that the tensile force produced by shrinkage tends to pull the diaphragm wall, which makes an enlargement to the deflection under earth pressure. This paper describes the layout of retaining structure, ground conditions, excavation procedures, and monitoring installation. Monitoring data shows that concrete shrinkage in the super-long RC strut will produce tension to the supporting structure. The influence of concrete shrinkage and relative controlling strategy are suggested in the end.