This paper presents an innovative design of a sample environment equipment for investigating SA508-3 steel under combined corrosive liquid and tensile loading conditions. The design consists of a mechanical system (MS) and a hydraulic system. The former establishes a mechanical link to transmit tensile force to a single edge notched tension steel sample and to create a cyclic corrosive liquid flow chamber. The latter supplies corrosive liquid to the flow chamber. Development of the MS with its features are reported. Preliminary offline test results revealed that the sample environment reached a maximum testing pressure of 0.3 MPa without leakage. Offline test results were consistent with those cylindrical ones tested previously. With this sample environment, a future in situ neutron diffraction (ND) experiment is described. The sample environment equipment maybe feasible for both offline and future ND investigation of SA508-3 steel, etc., under cyclic corrosive liquid and tensile loading conditions.