PROBLEM TO BE SOLVED: To develop new use of aqueous natural gas-associated water the broad industrial use of which is expected, so as to develop application commercial products in respective fields of agriculture, fishery, medical care, food, cosmetics, chemical products and the like. SOLUTION: Plant cultivation fertilizer, a plant activating agent and a plant growth assisting agent each includes aqueous natural gas-associated water. A plant cultivation method comprises using them. A method for culturing seaweed, and fish and shellfish and a method for culturing microorganisms comprise using the aqueous natural gas-associated water. Food, a cosmetic composition, soap, bath agents or hair restorer, an antibacterial/antiseptic agent, deodorant and medicinal products each contains the aqueous natural gas-associated water. COPYRIGHT: (C)2011,JPO&INPIT