A guidance for the optimal installation and maintenance of silt curtains is proposed based on the analyses of existing guidances, results of field measurements, and survey results of domestic and foreign situations. The proposed guidance focuses especially on the criteria of current speed and wave height for the performance of silt curtains as well as the optimal layout. According to two existing field measurements, the efficiency of a silt curtain of fixed hanging type is only approximately 20-30% in the area of the mean current speed of 20-30 cm/s. Additionally, even for a relatively weak storm periods without dredging, the significant wave height of 0.5 m, in a shallow coast of the water depth of 6m with silt curtains of which the depth is 3 m, the suspended sediment concentration near the silt screen can easily reach the peak value of the sediment plume caused by dredging. This proposed guidance is only a step and draft for more general applicability. Thus further improvement by more detail studies is required.