Use of a pectinase during preparing handmade papers from bast fiber of paper mulberry(Broussonetia kazinoki Sieb.) was investigated in order to decrease cooking chemicals and environmental pollution. For this purpose, four kinds of commercial pectinases, Rapidase LIQ(RLP), Rapidase Press(RP), Rapidase C80L Max(RCM) and Pectinase SS Kyowa(PSK) were used. And the durability of handmade papers before and after pectinase treatment was determined. RP and PSK had higher pectinase activity ad lower cellulase activity. The bast fiber was not defibered when pectinase was used. In order to increase the efficiency of enzymes, the bast fiber were treated ammonium oxalate(AO) or $K_2CO_3$under mild conditions. The AO pretreatment with those produced by $K_2CO_3$. The RP treated pulps after mild $K_2CO_3$cooking of the bast fiber were defibrated more easily than untreated pulp. The handmade paper prepared with the RP treated pulps after mild $K_2CO_3$cooking has good strength properties such as breaking length and folding endurance. Also, it has higher durability on heat aging, though its brightness was slightly lower than that of untreated paper.