Periodic mesoporous organosilicas (PMOs) are prepared using bridged silsesquioxane as the precursor and surfactant as the structure-directing species via sol-gel route. They are novel functional materials with many excellent and special properties, such as high surface area, ordered pore channel, sharp pore size distributions and so on. In this paper, the main advances in the research of PMOs in recent years are reviewed. The structural characteristics are particularly introduced. Then according to the different organic bridging groups incorporated into the structure, the PMOs are classified into three classes. The synthesis of PMOs with different template is introduced and the exterior factor which influenced the property are discussed. At last, the difficulties of research on PMOs are mentioned, and the development prospect is looked forward.

Contents
1 Introduction
2 Features of the structure for PMOs
3 The classification of PMOs
3.1 Alkyl-PMOs
3.2 Aryl-PMOs
3.3 Heterocycle-PMOs
4 The preparation of PMOs
4.1 Using ionic surfactant
4.2 Using non- ionic surfactant
5 Factors influencing on the properties of PMOs
5.1 The influence of inorganic salt
5.2 The influence of organic compound
5.3 The influence of PH value and temperature
6 Application of PMOs
6.1 Thin film and low-dielectric constant PMOs
6.2 Adsorptive material
6.3 Catalyst
6.4 Other new application
7 Conclusion