纵向数据分析；高维数据分析；分类和聚类分析。
代表论文：
1. Peirong Xu, Ji Zhu, Lixing Zhu and Yi Li (2015). Covariance-enhanced discriminant analysis. Biometrika, 102: 33-45
2.Peirong Xu, Lixing Zhu and Yi Li (2014). Ultrahigh dimensional time course feature selection. Biometrics, 70: 356-365
3.Tao Wang, Xu Guo, Lixing Zhu and Peirong Xu (2014). Transformed sufficient dimension reduction. Biometrika, 101: 815-829