The self avoiding walk(SAW) tail chain on diamond lattice was studied in this work.The permitted conformational number C(D) 1(N) and the mean square end to end distance h (D) 1(N) 2 as function of the chain length N for such a model tail chain were obtained by the computer simulations including the exact enumeration and Monte Carlo method.These two basic quantities obeyed the relations deduced from the scaling law.The critical exponents and the lattice indexes obtained from C (D) 1(N) and [h(D)1(N)]2 were given by fitting the data of the computer experiments.It was shown that there is a certain extension in the size in the direction normal to the wall for the SAW tail chain as well as for the normal random walk tail chain.The normal component of the mean square end-to-end distance is almost as twice as the parallel component of the short chain SAW.However

as N→∞

the effect of the wall on the chain conformation becomes weak because of the self-avoiding behavior for the model.It was identical with the result obtained from the SAW on the simple-cubic lattice.