PURPOSE: A sealant for sliding parts, containing water as a base material within a specific range in a tackifier, having a moderate viscosity and elasticity, non- toxic and harmless to the human body, and capable of preventing the leakage of a gas under pressure difference from the sliding parts.

CONSTITUTION: A sealant for sliding parts obtained by incorporating 0.1W100pts., preferably in an amount to give within 5W20,000 poises viscosity range at 25°C in one pts.wt. tackifier, e.g. polyethylene oxide, and if necessary adding a defoaming agent, etc. thereto.

EFFECT: The sealant is capable of adhering closely and completely to the sliding parts even on movement thereof, sealing the sliding parts, insoluble in liquefied gases, and stable at living temperatures for a long term without deteriorating nor degrading product phases. For example, the sealant is suitable to sealing agent for sliding parts, e.g. aerosol containers containing the liquefied gases as a propellant and foods or cosmetics packed therein.