Abstract：How does IT bring competitive advantage to the firm andpromote firm performance is concerned by multitudinous scholars. The relation among IT competency, knowledge management strategy, and organization performance under environment pressure was discussed. By taking 397 firms as the samples, the model was tested. And the results showed that the IT competency has a positive impact on organization performance through knowledge management strategy. Firms which implement knowledge management strategy can achieve higher performance level. Although environment pressure has a direct negative impact on the organization performance, it can also affect organization performance indirectly and positively thoughtIT competency and knowledge management strategy.