Wang Weihua, Ph. D student, graduated from Qingdao University of Science and Technology in June 2009 and the second year of doctor degree in East China University of Science and Technology now. My main subject is synthesis of multi-functional spherical polyelectrolyte brushes(SPBs) and characterization by small angle x-ray scattering(SAXS). SPBs consist of polystyrene(PS) cores onto which polyacrylic acid(PAA) are densely grafted which can be used as nanoreactors of synthesis of nano-mental particles, magnetic particles and adsorption of proteins. SAXS can be applied to characterize (1)particle size, shape and distribution; (2)particle dispersion; (3)particle volume fraction and specific surface area; (4)interfacestructure and the degree of phase separation between the particles and medium; (5) the interaction between particles. SAXS is proved to be a result-statistical, test-rapid, sample-nondestructive and preparation-simple method compared with other nano-scaled analysis methods, such as SEM, TEM, AFM.