1 INTRODUCTION  
2 X-RAY SURVEY AND SAMPLE SELECTION  
2.1 The XMM-UNDF Survey  
2.2 X-ray Data Products  
2.3 The AGN Sample  
3 X-RAY SPECTRAL ANALYSIS  
3.1 Stacking Multiple Spectra  
3.2 Spectral Fitting and Modelling  
4 CORRELATION ANALYSIS OF THE SPECTRAL PARAMETERS  
4.1 Iwasawa-Taniguchi Effect  
4.2 Intrinsic Column Density versus Redshift  
5 X-RAY VARIABILITY AND BLACK HOLE MASS-LUMINOSITY RELATION  
5.1 The Normal Excess Variances  
5.2 The BH Mass Estimation  
6 THE EDDINGTON RATIO DISTRIBUTION  
6.1 Eddington Ratio vs Other Parameters  
7 SUMMARY AND CONCLUSIONS