This paper describes NTTS participation in the Blizzard Challenge 2008. The Blizzard Challenge 2008 extended the evaluation languages to Mandarin. In this year, the basic NTTS system was updated with a new Mandarin phrase prediction module. According to the listening evaluation results, all three aspects of English voice, similarity, MOS and word error rate, have been improved slightly. However, the performance of Mandarin voice was not as good as we expected. Some result analyses on Mandarin voice are presented in this paper.