Stonecutters Bridge will have a main span of 1018m to cross the Rambler Channel in Hong Kong, China. The 1596m long cable stayed bridge has a steel main span and concrete back spans. The tapered mono column towers stand on the bridge centre line between the twin deck box girders, which are connected with 

cross girders. The towers are concrete to +175m and composite with an outer stainless steel skin to +293m, topped by a lighting feature to +298m. Stay cables are in 2 planes in a modified fan arrangement attached to the outside edges of the deck girders. The concrete back span decks are monolithic with the three intermediate single shaft piers and the portal end piers. Both sides of the bridge are on reclaimed land and foundations are large diameter bored piles to bedrock.  Short span bridges in Hong Kong are designed for a 5%g nominal lateral earthquake load. For long period structures design response\ spectra are required. For Stonecutters Bridge, these were developed for various return periods using a Probabilistic Seismic Hazard Assessment (PSHA). The effects of the local soil profile were also explicitly considered. The paper summarizes the PSHA and how the effects of the local soil profile were taken into account using a one dimensional non-linear dynamic site response analysis to determine the design spectra at ground level. The methods used to determine the dynamic response of the bridge and the effects of non synchronous motion of the foundations are also presented.