Cryptographic properties of the single cycle T-functions output sequences are investigated. Bounds of autocorrelation functions of the kth coordinate sequence and bounds of state output sequence are calculated respectively. The Maximum Sidelobe Ratio (MSR) of the kth coordinate sequence and the MSR of state output sequence are given respectively. The bounds of autocorrelation functions show that the values of autocorrelation functions are large when shifts are small. Comparisons of the autocorrelations between the state output sequence and coordinate output sequence are illustrated. The autocorrelation properties demonstrate that T-functions have cryptographic weaknesses and the illustration result shows coordinate output sequences have better autocorrelation than that of state output sequences.