The present invention provides a clathrate compound characterized by containing: a polymolecular host compound as a host compound； and an agricultural chemical active ingredient having a saturated solubility in water at 25°C of not less than 500 ppm as a guest compound. The present invention also provides a method for controlling the concentration of an aqueous agricultural chemical active ingredient solution, characterized by containings a step of including an agricultural chemical active ingredient having high saturated solubility in an interior space formed of a polymolecular host compound, thereby maintaining the saturated solubility of the agricultural chemical active ingredient in water within a predetermined concentration range. The present invention also provides an agricultural chemical formulation containing the clathrate compound. The present invention also provides an agricultural active composition containing the clathrate compound and a synthetic pyrethroid.
