A new pattern of hierarchical ordering, strings of mesoporous silica spheroids, was synthesized at the interface of CO2-water emulsion systems by the utilization of the additive of Na2CO3 and the structure-directing agent of surfactant Brij 97. The strings were self-constructed with spheroidal particles to form linear and branched patterns. Many defects were observed, which should be important in the formation of mesoporous silica spheroids. Templating of CO2-water emulsion was believed to access the pattern in strings. This work provides one example of micro-construction of alternative morphology, which should be significant on designing the novel patterns of mesoporous silica particles. (C) 2003 Elsevier B.V. All rights reserved.