To provide a wrapping form of a triangular rice ball wherein both triangular surfaces and a base of the triangular rice ball are wrapped in a film in a form of a channel, then slopes of the rice ball are wrapped in extensions of the film, further four corners of the film are overlaid on the triangular surface of the rice ball, and a paper label is stuck so that a sealed wrapping form can be obtained, and one of the slopes of the rice ball can be exposed in a broadening manner with a triangular bag shape kept by tearing the paper label slantly.

The wrapping form comprises a slant tear-to-open string 2 welded to the vicinity of one of widthwise ends of the rectangular wrapping film 1 and a notch 3 provided. To unseal the wrapping form, the paper label 4 is twisted by 180° from an initial end 2a for tearing the label to slantly tear off the paper label 4.