In a sample of 37 adolescents and young adults with autism spectrum disorder (ASD) and 35 typically-developing controls (TDC), we investigated sensory symptoms by clinical measures, and Mismatch Negativity and P3a component at Fz with the frequency and duration oddball paradigms of event-related potentials. Results showed that compared to TDC, ASD participants reported more sensory symptoms, and presented a shorter P3a peak latency in the duration paradigm, which was correlated with more social awareness deficits. In the frequency paradigm, P3a parameters were correlated with sensation avoiding and attention characteristics of ASD. Our findings suggest that sensory abnormality in ASD may extend into adolescence and young adulthood. P3a latency might be a potential neurophysiological marker for ASD.