A parallel-group, randomized, open-label study will be performed in subjects receiving PCV7 and subjects receiving controlled vaccine Hib vaccine, to claim the efficacy of PCV7 in the prevention of NP carriage of vaccine-serotype S. pneumoniae (serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F combined) in 2 to 5 years old healthy Chinese children.