The shapes and types of containers for foods, drugs and medicines, and cosmetics and detergent refills are diverse: glass bottles, cans, PET bottles and laminate-film liquid packaging bags are examples. In recent years, to increase the ease of pouring out the contents of laminate-film liquid packaging bags, the shape of the heat seal has been changed from a flat seal to a bottleneck seal. However, the large number of bottleneck seal ruptures of liquid packaging bags due to impact load during the transport, loading and unloading of packaged products has been a problem. In our previous study, we investigated impact peel strength in the heat-sealed area of a laminate film; however, the effects of the bottleneck seal shape and heat-sealed area width on impact peel strength and rupture occurrence have not yet been clarified. In this study, experiments were carried out to clarify the effects of the flat and bottleneck seal shapes, as well as heat-sealed area width, on impact peel strength and bag rupture occurrence. The following two films were used : (1) a multilayered laminate film with barrier characteristics against oxygen and water vapor, which is frequently used for liquid packaging bags owing to its high efficacy in food quality preservation, and (2) a multilayered laminate film without barrier characteristics. On the basis of the results obtained, we established, for the first time, a new standard regarding bottleneck seal shape and heat-sealed area width.