Abstract: Latour brought forward the new principle of symmetry that abolished the distinction of nature and society to turn to the construction of science from the social construction of science, according to his new explanation about the reason of science’s formation. Based on this, he thought science was constructed in the actor-network and society appeared during this process, which turned to a new view of science. He claimed to reassemble the social in the construction of science by putting forward Actor-Network-Theory, in order to realize the subject-object unity. Latour thought he broke away from the camp of social constructivism, but by investigating the relationship of the unity between Actor-Network-Theory and Strong Programme, we find his theory still insists on the general principle of the social constructivism of science, and in fact makes the supplement and development for the broader social constructivism.