Combination of prior knowledge and implicit knowledge hidden in the data of system can enhance the quality of information services in Knowledge Grid. Fuzzy Cognitive Maps (FCMs) are constructed by experts using prior knowledge and do not acquire the implicit knowledge from the data of systems directly, which may distort the dynamical behaviour of information services systems in which knowledge representation and reasoning are based on FCMs. We propose a global concept of FCMs method to acquire implicit knowledge and modify the false knowledge maybe done by experts from the data of system. Experiments show that this method can acquire the implicit knowledge from the data of system and modify the false knowledge hidden in FCMs, which makes the learned FCMs that acquire knowledge from the data of system more natural than the FCMs constructed by experts to emulate intelligent information services behaviors in Knowledge Grid.