Abstract: A dental floss holding structure includes a dental floss and two holding bodies. The two ends of the dental floss are respectively connected with a base, which includes a first coupling portion with a first positioning portion mounted thereon. Each of the two holding bodies includes a second coupling portion corresponding to the first coupling portion, and the second coupling portion has a second positioning portion corresponding to the first positioning portion, so that the dental floss and the holding bodies can be stably fixed with each other through the engagement between the first and the second positioning portions. Accordingly, when the user's hands hold the two holding bodies to clean the teeth slits, the fingers can be kept out of the mouth without entering the mouth, which not only provides convenience but also assures the hygiene.