Complex mixtures of a DNA/protamine complex with 30%, 50%, and 70% DNA/chitosan complex were prepared for a soft type of membrane for guided bone regeneration. All complex mixtures showed flowable properties when kneading the mixture with distilled water. Increases in the mixture ratio of the DNA/chitosan complex in the complex mixture increased the consistency of flowable complex mixture. Differences in biodegradable rates among three complex mixtures were observed in vivo. Although the complex mixture with 30% DNA/chitosan complex completely disappeared, part of the other complex mixtures remained 3 months after implantation. Biodegradable rates of mixtures with higher volumes of the DNA/chitosan complex were slower. In conclusion, all complex mixtures showed flowable properties. Their consistency and biodegradable rates could be controlled by the mixing ratio between DNA/protamine and DNA/chitosan complexes. They are promising candidates for biodegradable membranes with adjustable biodegradable rates that form desired figures by hand during surgery.