The present invention discloses a clay/amine complex which is an excellent surfactant and a good reinforcing agent of polymers. The complex of the present invention can be produced by modifying layered inorganic silicate clay such as montomorillonite, with an intercalating agent, AMO (amine terminal-mannich oligomer). The AMO can be obtained by polymerizing polyoxyalkylene amine having molecular weight over 1000, p-cresol and formaldehyde. The present invention further discloses a nanosilica plate, which can be obtained by extracting the above complex with a hydroxide or a chloride of alkali metal or alkaline-earth metal, and consequently, the AMO intercalating agent can be recycled for reusing.