Metabolic changes of bone have been recognized as one of postgastrectomy sequlae. Howev- er,there have until now been no reliable methods to provide an accurate assessment of bone mass status,resulting in a wide variation of the reported incidences of postoperative metabolic bone disorders.Recently an improvement in measuring bone mineral status was achieved using dual energy x ray absorptiometry(DEXA). In order to evaluate bone mineral density after various kinds of gastrectomy procedures, fourty five male patients who underwent the surgery for the stomach and colorectal cancer were studied. Group I was consisted of 13 patients who underwent total gastrectomy,groupII consisted of 16 patients with subtotal gastrectomy with gastroduodenostomy reconstruction (Billroth I), group m,of 9 patients with subtotal gastrectomy with gastrojejunostomy reco- ntruction, and control group,of 7 patients with colorectal resection. Measurement of lumbar spine bone mineral density in patients who had gastrectomy(0.84k0.14 g/cm2 in group I,0.88 +0.16 in groupII,and 0.82+0.14 in groupIII) was significantly lower than that of patients who underwent colectomy(control group 1.03k0.18 g/cm'). Serum hemoglobulin(12+1.19 gm/dl) and total calcium(4.75+0.21 mEq/L) levels in patients with gastrectomy were signifi- cantly lower than those of colectomy group(14.1 +0.85 and 4.75 +0.10, respectively). This study demonstrates that in postoperative bone mineral density and serum total calciurn level there are no differences among patients with various gastrectomy types, however, lower values than in patents with colectomy. (Korean J Gastroenterol 1994; 26: 800 805)