In general relativity, Mercury’s orbit becomes approximately elliptical and the its perihelion has thus an additional advance. We demonstrate, meanwhile, that in comparison of those given by Newton’s theory of gravitation for the orbit of the Mercury, the circumference and the area are reduced by 40.39 km and 2.35 × 109 km2, respectively, besides the major-axis contraction pointed out recently, and all are produced by the curved space within Einstein's theory of gravitation. Since the resolution power of present astronomical distance measurement technology reaches one kilometer, the shrinkage of Mercury’s orbit can then be observable.