China's health ministry said 104 out of 12,892 babies showed serious symptoms.
Four infants have died after drinking the milk of the Sanlu Group containing the industrial chemical melamine, which could cause urinary problems.
Meanwhile, in Hong Kong, a toddler has been diagnosed with a kidney stone after drinking the powder - the first such case outside mainland China.
A number of Asian and African countries have now banned Chinese dairy imports following the scandal.
Chinese police have arrested 18 people in connection with the scandal.