Abstract: From the matrix theory and cellular automata theory, this paper presentes the homogeneous characteristic methodology of cellular automata. The methodology utilizes the state transition matrix equation and its characteristic polynomial to analyze the rule 90 and 150 additive cellular automata, and proves that if the characteristic polynomial of null boundary rule 90 and 150 linear cellular automata is non-dividable, then the states transition diagrams of the null boundary rule 90 and 150 additive cellular automata responding to the linear cellular automata have identical structure but have different states. Research indicates that this methodology have advantages in the application fields of pseudorandom sequence generation, communications, and test.