Benzamidine derivative of the formula 1 or pharmaceutically acceptable salts thereof: wherein R 1 is methyl; ethyl; propyl; isopropyl; butyl; t-butyl; pentyl; cyclopentyl; hexyl; cyclohexyl; phenyl; aminomethyl; aminoethyl; amino; isobutylamide; guanidine; 1-propyl-piperidino; 2-morpholinomethyl; NR 6 R 7; CH 2 NR 6 R 7; wherein A is C 1 ∼C 6 alkyl and n is an integer of 2 to 6; pyridinyl; 4-hydroxypiperidinomethyl; cyclohexylaminomethyl; R 2 is hydrogen; methyl; ethyl; isopropyl; propyl; butyl; isobutyl; methoxymethyl; hydroxymethyl; 2-methylpropyl; pentyl; chloromethyl; chloroethyl; cyclopentyl; cyclopentylmethyl; cyclohexyl; benzyl; vinyl; R 3 and R 4, each independently, are hydrogen; halogen; hydroxy; cyclohexylamino; methoxy; C 1 -C 4 alkanoyloxy; C 1 -C 7 aliphatic alkoxy which is substituted by carboxy, esterified carboxy or amidated carboxy; R 5 is hydrogen or hydroxy; R 6 and R 7, each independently, are hydrogen; methyl; ethyl; propyl; benzyl; pyridin-3-yl; pyridin-4-yl; 2-morpholinoethyl; 4-pyridinylcarbonyl; 3-pyridinylcarbonyl; isobutylcarbonyl; ethanesulfonyl; methoxyethyl; hydroxyethyl; hydroxyacetyl; methoxyacetyl; Y is oxygen; sulfur; NR 6; CH 2; X 1 and X 3, each independently, are oxygen; sulfur; amine; methylamine; X 2 is propylene; pentylene; hexylene; heptylene; ethylene-O-ethylene; 3-hydroxy-3-methyl-pentylene; methylethylene-NH-ethylene; ethylene-NH-ethylene; propylene which is interrupted by piperazine; butylene carbonyl; 2-butenyl; methylene-phenylene-methylene; methylene-pyridylene-methylene; 1,2-ethylene-1,4-phenylene-1,2-ethylene; 1,3-propylene-1,4-phenylene-1,3-propylene; 1,2-ethylene-naphthalene-1,2-ethylene; with the proviso that if X 1 and X 3 are oxygen, X 2 is pentyl and R 3 and R 4 are hydrogen, the compound of the formula 1 wherein R 1 is methyl and R 2 is isopropyl is excluded. R 1 is methyl; ethyl; propyl; isopropyl; butyl; t-butyl; pentyl; cyclopentyl; hexyl; cyclohexyl; phenyl; aminomethyl; aminoethyl; amino; isobutylamide; guanidine; 1-propyl-piperidino; 2-morpholinomethyl; NR 6 R 7; CH 2 NR 6 R 7; wherein A is C 1 ∼C 6 alkyl and n is an integer of 2 to 6; pyridinyl; 4-hydroxypiperidinomethyl; cyclohexylaminomethyl; R 2 is hydrogen; methyl; ethyl; isopropyl; propyl; butyl; isobutyl; methoxymethyl; hydroxymethyl; 2-methylpropyl; pentyl; chloromethyl; chloroethyl; cyclopentyl; cyclopentylmethyl; cyclohexyl; benzyl; vinyl; R 3 and R 4, each independently, are hydrogen; halogen; hydroxy; cyclohexylamino; methoxy; C 1 -C 4 alkanoyloxy; C 1 -C 7 aliphatic alkoxy which is substituted by carboxy, esterified carboxy or amidated carboxy; R 5 is hydrogen or hydroxy; R 6 and R 7, each independently, are hydrogen; methyl; ethyl; propyl; benzyl; pyridin-3-yl; pyridin-4-yl; 2-morpholinoethyl; 4-pyridinylcarbonyl; 3-pyridinylcarbonyl; isobutylcarbonyl; ethanesulfonyl; methoxyethyl; hydroxyethyl; hydroxyacetyl; methoxyacetyl; Y is oxygen; sulfur; NR 6; CH 2; X 1 and X 3, each independently, are oxygen; sulfur; amine; methylamine; X 2 is propylene; pentylene; hexylene; heptylene; ethylene-O-ethylene; 3-hydroxy-3-methyl-pentylene; methylethylene-NH-ethylene; ethylene-NH-ethylene; propylene which is interrupted by piperazine; butylene carbonyl; 2-butenyl; methylene-phenylene-methylene; methylene-pyridylene-methylene; 1,2-ethylene-1,4-phenylene-1,2-ethylene; 1,3-propylene-1,4-phenylene-1,3-propylene; 1,2-ethylene-naphthalene-1,2-ethylene; with the proviso that if X 1 and X 3 are oxygen, X 2 is pentyl and R 3 and R 4 are hydrogen, the compound of the formula 1 wherein R 1 is methyl and R 2 is isopropyl is excluded.