Biodegradable polymer droplet containing natural magnetic nanoparticle is composed for smart drug delivery and heat treatment. For selective and efficient drug delivery to the target tissue, direct high magnetic field will be applied near the target tissue. For drug release control and heat treatment, alternative high magnetic field will be applied. Magnetosome, natural magnetic nanoparticle, is extracted from magnetotactic bacteria, AMB-1. Mixture of magnetosome and sodium alginate composes into droplet using the microfluidic device applied Plateau-Rayleigh instability principle. The magnetosome contained droplet selected its rout at the bifurcate microchannels by direct high magnetic field. High alternative magnetic field generating circuit is designed with 18 mT and 4 Hz magnetic wave. The generated magnetic wave was applied to the extracted magnetosomes so that temperature of the magnetosomes increased from 15.2°C to 17.6°C.