A composition comprises an active ingredient contained within a microcapsule having a shell comprises a urea-formaldehyde resin. Preferably the active ingredient is clomazone and the composition is a herbicidal composition. Also claimed is a method of preparing a microencapsulated composition comprising an encapsulated active ingredient, the method comprises preparing a urea-formaldehyde prepolymer by the reaction of urea and formaldehyde； dispersing the active ingredient and a water insoluble liquid carrier in an aqueous phase to form an emulsion； and adding the urea-formaldehyde prepolymer to the emulsion and allowing the components thereof to react to form microcapsule walls at the interface of the dispersed organic phase and the aqueous phase, so as to encapsulate the organic phase.
