The present application relates to a needleless syringe for injecting an injection objective substance into an injection target area without using an injection needle. In one aspect, the needleless syringe includes a main syringe body containing the injection objective substance with the use of a sealing member, a pressurizing unit provided in the main syringe body and configured to pressurize the injection objective substance, a flow passage unit defining a flow passage of the pressurized injection objective substance to be discharged to the injection target area and a preparatory filling unit configured to fill the flow passage unit with a part of the injection objective substance by destroying a part of the sealing member before the injection objective substance is pressurized. According to some embodiments, it is possible to mitigate the load exerted on the nozzle during the injection and reduce the noise without deteriorating a syringe user convenience.