Abstract: A class of chaotic sequences generated by piecewise linear (PWL) mappings and noninvertible transformation is proposed as the spreading codes in An A-CDMA system. The theoretical analysis shows that the chaotic sequences serve as spreading codes for A-CDMA. The effect of the finite precision and the length of spreading gain on the properties are investigated by means of computer experiments. The result shows that the properties of chaotic spreading sequences are superior to those of m-sequence, and the number of obtained sequences is found to be larger than the number of m-sequences of the same length. The feasibility of the chaotic sequences as spreading codes for A-CDMA is verified.