In order to investigate the effects of magnetized water treated with HI-Scalper153^R on body performanceand ammonia concentration in feces of broiler chicks, a feeding trial was conducted with a total of 180broiler chicks. Each treatment had 18 chicks with 5 replications. Chicks during experimental periods, broilerchicks were fed magnetized water and subterranean water, respectively. The results obtained summarizedas follows: Body weight gain slightly increased for broiler chicks fed magnetized water compared withcontrol. But, there is no significantly (p=0.36) different among treatments. Feed intake significantly (p=0.046)decreased for broiler chicks fed magnetized water compared with control. Feed efficiency was significantly(p=0.020) improved for broiler chicks fed magnetized water of each periods when compare to the control.Especially, in starter periods, the feed efficiency of magnetized water treatment increased by 10% more thancontrol (1.80 vs 1.69). In feces, average ammonia concentration (ppm) significantly (p=0.004) decreased inthe magnetized water treatment compare to control. Especially, the magnetized water treatment decreasedby 2.2 times compared to the control in ammonia concentration of feces (83 vs 37ppm).