Abstract: A blast-resistant cargo container includes side panels and connecting members. The connecting members are mounted between the adjacent side panels to create a frameless structure of the cargo container. Under ordinary conditions, the structure still has sufficient stiffness for loading goods. When an explosive blast occurs in the cargo container, the structure is flexible and utilizes membrane strength in the entire container structure, whereby the cargo container is capable of withstanding the explosive blast. Bottom perimeter bars are able to be mounted around a bottom surface of the cargo container. Grooves are defined in the perimeter bars and L-shaped flanges are formed on one end of the connecting members. Therefore, by receiving the L-shaped flanges into the grooves, the perimeter bars are securely connected with the side panels.