As raw water quality gets worse, a great number of advanced techniques have been developed and adapted for water treatment to provide safe and high-quality drinking water. One of various water treatment processes is biological treatment, which is suitable for advanced water treatment, followed by conventional treatment processes. In this paper, we propose ozonation and biofiltration by a rope-type biofiltration contactor for the effective removal of natural organic matter (NOM) from the source of drinking water. The removal efficiencies of NOM were evaluated under various experimental conditions, such as ozone contact time, empty bed contact time (EBCT), media density of the sedimentation tank, and turbidity of the raw water. The combination of pre-ozonation and bio-filtration was found to be very effective for removing biodegradable organic matter as well as the turbidity of raw water. We expect that the biological rope media biofiltration contactor, with pre-ozonation, may be complimentary units for NOM removal when employed in a conventional water treatment process. This process can be easily introduced in small-and medium-scale water purification units.