Currently, 1 ounce of gold is about US$620 = HK$4836. You were asking about the cost of 1 kg of gold. 1kg = 2.2046 lb = 35.274 oz. Therfore 1kg of gold is worth HK$170,585--
To measure precious metals, we will use troy ounce instead of ounce. 1 kg=35.27 ounce is correct but 1 kg=32.15 troy ounce. So, 1 kg gold is about HK$155,477. You may refer the following web-site : http://www.goldcalculator.com/index_files/page0033.htm