In the growth process of movie IWOM, the antecedent IWOM has a significant influence on the subsequent IWOM. IWOM does not form all at once, but iteratively over a short period. This article explores the influence of IWOM publishers on IWOM growth and the dynamic impact of IWOM on movie box office by using vector autoregressive model (VAR model) and impulse response analysis. The findings reveal that highly influential and active users' statements stimulate discussion enthusiasm and increase related topic discussions. These statements also reduce the discreteness of IWOM. On the other hand, highly professional users make IWOM more discreet. Both increased discussion enthusiasm and differentiated IWOM contribute to the growth of movie box office. Additionally, during the growth of IWOM, there is an approximately five day “advance period of word-of-mouth regeneration”: it takes audiences about three days from reading movie reviews to watching a movie, followed by about two days to write their own reviews, and the whole process takes about five days.