Spatial Reference of HK

The spatial reference of Hong Kong could be found at : http://spatialreference.org/ref/epsg/2326/

There is a link "Proj4" in that page which provides the Proj4js definitions for converting EPSG:2326 (HK1980 Grid) projection to other projection using the Proj4js library:

+proj=tmerc +lat_0=22.31213333333334 +lon_0=114.1785555555556 +k=1 +x_0=836694.05 +y_0=819069.8 +ellps=intl +towgs84=-162.619,-276.959,-161.764,0.067753,-2.24365,-1.15883,-1.09425 +units=m +no_defs