Cellulose nanofiber having a cross-section with a nano-scale can be used in various fields due to excellent properties of cellulose fibers. In particular, it was confirmed in the paper industry, the possibility of material savings of the raw pulp and strength improvement of the paper with the cellulose nanofiber. Cellulose nanofiber having a high aspect ratio and a micrometer length is called to cellulose nanofibrils(CNF), nanofibrillated cellulose(NFC), microfibrillated cellulose(MFC), etc. and it is commonly prepared by mechanical isolation such as grinding. However because the problem of mechanical isolation is high manufacturing cost, it is important to facilitate to prepare MFC through various pretreatment.
In this study, for the preparation of MFC with low mechanical shearing, MFC was prepared by grinding after enzyme beating as environmentally friendly pretreatment and to evaluate characteristics of MFC and properties of handsheet added.

The results of this study were summarized as follow :
1. Among three kinds of endo-glucanases Denimax BT was most high activity at pH 6.0 - 8.0 and more than 50℃, the change in temperature was less activity at the same pH.
2. Due to enzyme beating, the time to reach the same freeness was reduced than control and the efficiency of Denimax BT was most high by 55.6%.
3. The viscosity of MFC suspension prepared after enzyme beating was lower than control and as the grinder pass number increases, the viscosity was increased.
4. On the microscope as the grinder pass number increases, fine fiber was increased and MFC sheet surface was smooth. Also the pores in MFC sheet surface were reduced but there was no significant difference due to the enzyme beating. Aspect ratio of MFC was highest at 5pass and after that it was little reduced. Among three kinds of endo-glucanases aspect ratio of Denimax BT was highest.
5. As the grinder pass number increases, crystallinity of MFC sheet was decreased but after that it was little change. Also, crystallinity of MFC manufactured after enzyme beating was higher than control. Sugar composition of MFC sheet was made up of glucose and xylan and there was no significant difference due to grinder pass number or enzyme beating.
6. Properties of handsheet added MFC shown that WRV, tensile index and tear resistance was increased and air permeability was decreased as grinder pass number increases. But bulkness was no significant difference. Properties of handsheet added MFC prepared after enzyme beating was higher than handsheet added control.