A spreadable box includes a bottom portion, a plurality of sidewall portions, and at least one support tab. The plurality of sidewall portions is extended from the bottom portion. The at least one of the plurality of sidewall portions includes a pair of sidewall planes folded to overlie each other with a space there between. The at least one support tab is protruded from at least one of the plurality of sidewall portions and configured to be inserted into or withdrawn from the space in order to secure the box in an assembled form or a spread form.