Abstract: This paper presents a volume-preserving approach for animating liquid flows modeled by metaballs. A volume of liquid can be adjusted to a previous volume by using the influence radius and the maximum density of metaballs as volume-controlling parameters. Recursive subdivision is used to efficiently calculate the volume of implicit surfaces. The criterion for subdivision is obtained by using the concept of interval analysis and the common property of metaball density functions. Providing a sequence of parameters, the volume-compensation region can be controlled according to the substance making up the object, resulting in local preservation of the volume. Set partition is used for determining isolated surfaces in order to apply local-volume preservation.