Abstract: The present invention relates to a heat/temperature preserving pack. Embodiments of the heat preserving pack include a soft pack or a hard box pack, having an inner containing space filled with phase change isothermal substance. The present invention maintains the temperature of objects for an extended period to achieve a constant temperature effect. By implementing the present invention, the size and weight of the heat preserving container is effectively reduced and the space available for storing objects to be heat preserved is increased. Thus, the heat preserving container is convenient to carry and the transport cost is reduced.