The hairy root was induced form potato tuber disc by infection of a. rhizogenes. The detection of the agropine and mannopine by paper electrophoresis confirmed that induced hairy root was transformed by A. rhizogenes. The activity of peroxidase was the highest at 5 weeks and isozyme pattern of peroxidase revealed 3 cathodic bands and 2 anodic bands and new C4 band(pI 4.6) was observed at 7 weeks after cultivation in hairy root was isoelectric focusing. To study the effect of Ca2+ on cell wall formation in hairy root, channel blocker of Ca2+ was treated. The activity of $eta$-glucan synthetase II(GS II) related to cell wall synthesis was inhibited by about 50% in diltiazem and flunarizine treatment than that of control, but stimulated in CaCl2 treatment. Therefore these results showed that Ca2+ might be an effective factor in the cell wall formation. The activity of GS II by NaF treatment was increased by about 30%. This result suggested that the activity GS II is changed through phosphorylation process.