The influence of builders on calcium deposition on the fabric was studied by laundering the cotton fabric with sodium carbonate, sodium metasilicate, sodium tripolyphosphate and built detergents in hard water. The laundry variables were: 1) Washing cycles: 5, 10, 20, 30 and 40 cycles. 2) Water hardness: 100 ppm, 150 ppm, 200 ppm and 300 ppm. 3) Builders: Na_2 CO_3, Na_Z Si0_3 and STPP. 4) Detergents: Na-DBS, Na-DBS+Na_2C0_3, Na-DBS+Na_2 Si0_3, Na-DBS+STPP, Na-DBS+Na_2 C0_3+STPP, and Na- DBS+Na_2 Si0_3+STPP. The fabric was washed for 15 minutes at 23+1℃ in a washing machine(Gold Star WP 3007) under the similar condition with those of home laundering, and rinsed 3 times in the same water hardness for 5 minutes. The calcium deposits on the fabric was determined by EDTA-BACK titration methods. The results of this study were as follows: 1) The amount of calcium deposits on the fabric was increased with increasing wash cycles. This deposit was due to the build up of insoluble calcium carbonate. 2) As the water hardness increased, the amount of calcium deposits on the fabric was increased. 3) Alkaline builders, such as, Na_2CO_3 and Na_2Si0_3, promoted calcium deposition on the fabric, however STPP prevented calcium deposition on the fabric. 4) Fabric laundered with Na-DBS+Na_2C0_3 showed the highest calcium deposits on the fabric, and decreased with the order of Na_2C0_3, Na-DBS+Na_2Si0_3, and Na-DBS. And fabrics washed with phosphate-built detergents showed a small amount of calcium deposition.