Exact results are obtained for the Ashkin-Teller model on a special Si
erpinski carpet (SC). We calculate the partition function and correlat
ion function with the transformation matrix method. Thus the asymptoti
c behaviour of the correlation function is investigated in the Limit o
f long distance. The results show that no phase transition occurs at a
ny finite temperature for the finite R (the order of ramification) fra
ctal, which is consistent with the conclusion of the Ising and Potts m
odel.