The correlation dimension for the time series of blast furnace process varisble,such as blast volume, burden pressure drop and blast pressure etc.,have been estimated by using GP and modified GP algorithms.The predictublity analysis for the process variables have also been investigated.The results show that it is difficult to determine the chaotic attractor of blast furnace condition.It has been found that the predictablity for process variables can be used to niterpret and identity the precursor of biast furnace condition.