An easily openable packaging bag according to the present invention does not produce an opening piece resulting in a small piece of waste when opening, and facilitates opening even with a single hand. Furthermore the easily openable packaging bag of the present invention can be also applied to a packaging bag provided with barrier characteristics. The easily openable packaging bag joins both ends of a packaging material into a tube shape. Both of the joined ends are heat sealed to form a bonded rear portion in a rear portion of the tube portion and solid contents are contained in an inner section of the tube portion. A weakened portion is formed in a portion not occupied by the contents in the tube portion along a circumferential direction of the tube portion and the weakened portion is not provided in at least a portion of the bonded rear portion.