An alginate impression method for dental treatment is provided. The method comprises steps of: providing alginate in a squeezable pouch; providing water in a syringe; injecting the water into the squeezable pouch; closing the squeezable pouch; kneading the squeezable pouch so as to mix the alginate and the water inside; and squeezing out the mixed alginate and water from the opening of the pouch onto a mold so as to make an impression. The syringe may comprise a tube portion having a first opening and a second opening and a plunger configured to be fit into the second opening of the tube portion for piston pumping movement. The first opening may fit air-tightly with the opening of the squeezable pouch so as to inject water into the squeezable pouch.