Silver colloid nanoparticles, with high Ag+ concentration (up to 0.025 mol/L) and high stability (up to 5 months), have been synthesized via one step reduction of AgNO3 by glucose in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB). The reaction process, size distribution, morphology, and structure of particles have been characterized by UV/Visible absorption spectrophotometry, transmission electron microscopy (TEM) and X-ray diffractometer (XRD). Results indicate that CTAB accelerates the reaction between silver ions and glucose, because it stabilizes H+. TEM images show that silver sol consists of well-dispersed agglomerates of spherical nanoparticles with particle size from 10 to 40 nm.