The purpose of this study was to evaluate the sustainability of antibacterial effect against Streptococcus mutans of experimental fluoride varnish mixed with 2-hydroxyethyl methacrylate (HEMA) and/or glutaraldehyde. Experimental fluoride varnish (EX1) was fabricated. To make fluoride varnish with adhesive materials, EX1 was mixed with 5 wt% of glutaraldehyde (EX2), 35 wt% of HEMA (EX3) or both 5 wt% of glutaraldehyde and 35 wt% of HEMA (EX4). 5 μL of each experimental group was applied to 6 mm diameter polyethylene terephthalate film discs. Disks were stored in distilled water in a shaking incubator at 37℃ for 1 hour, 3 hours, 8 hours, 12 hours, 24 hours, 5 days and 10 days. The antibacterial activities against S. mutans were evaluated by agar diffusion test with the discs at each time. The antibacterial activities were sustained up to 10 days in all groups. The antibacterial activities of EX3 and EX4 were significantly higher than other groups from 8 hours to 10 days and there were no significant differences from EX2 at 10 days. HEMA with and without glutaraldehyde can be applied to fluoride varnish to increase the sustainability of antibacterial activities.