Abstract: A conceptual model was developed for the effect of interpersonal trust on the tacit knowledge transfer between corporations, since such a transfer relies on the mutual trust in a certain field of knowledge via the ″neighboring interaction″ through interpersonal exchange. Applying the structural equation to the model to verify it with the M&A implemented by Baosteel Group corporations as example, the results showed empirically that in the process of tacit knowledge transfer after M&A, the emotional trust has positive correlation with the willingness, worthiness and exploratory mode of tacit knowledge transfer, while the cognitive trust has negative correlation with the worthiness and exploratory mode of tacit knowledge transfer. Moreover, there is a positive correlation between institutional trust and willingness of tacit knowledge transfer.