In this study, hollow fiber membranes for forward osmosis using cellulose triacetate were prepared using the non-solvent phase separation method, and the water purification properties of the prepared membranes were tested. In order to optimize the membrane morphology, which affects the membrane performance, 1,4-dioxane and lithium chloride were used as additives. Using the forward osmosis process, the properties of the membrane were investigated according to changes in the factors such as the salt type, salt concentration, and solution temperature. In the nanofiltration process, the water flux was found to increase and the salt rejection to decrease with increasing air gaps, regardless of the type of salt. In contrast, in the forward osmosis process, the water flux increased and the solute rejection value increased in a manner similar to the increasing concentration of solute.