Skim milk powder was reconstituted in distilled water to obtain reconstituted milk A (8.44% TS), milk B (9.65% TS) and milk C (10.84% TS). The yogurts were produced from untreated milk and milk heat treated at 85°C/20 and 90°C/10 min, respectively. Milk samples were inoculated with 2.5% commercial yogurt culture and incubated at 43°C until pH 4.6 was reached. Viscosity measurements were performed at 20°C after 1, 7 and 14 days of storage at 4°C. Brookfield DV-E Viscometer (spindle No 3 at 20 rpm) was used for measurement. Initial viscosity of yogurt samples produced from milk treated at 85720 were greater, but yogurt samples produced from milk treated at 90°C/10 min showed a smaller decrease of viscosity during time of shearing. Viscosity of stored samples showed the smaller reduction during time of shearing.