Short-message (SM) is one of the most frequently used communication channels in mode society. Bazed on the SM communication records provided by some volunteers, we investigate the statistics of SM communication patte, including the inter-event time distributions between two consecutive short messages and two conversa-tions, and the distribution of message number contained in a complete conversation. In the individual level, the empirical result raises strong evidence that the human activity patte, exhibiting a heavy-tailed inter-event time distribution, is driven by a non-Poisson process.