The purpose of this study was to analyze the effect of hotz plate appliance to maxillary arch development of complete unilateral cleft lip and palate patient. The subjects were divided into two groups. The first group consisted of 6 patients, aged under two years with hotz appliance, recruited from Hasan Sadikin Hospital Bandung, and the second group, as control group, consisted of 6 patients, aged under two years, without hotz appliance, recruited from Haji Hosiptal Makassar. It was showed that in group with hotz plate appliance, no difference found on the size of anterior maxillary arch and minor maxillary arch. On the other hand, in the control group, minor maxillary arch was longer than major maxillary arch. It was concluded that hotz plate appliances affected that palatal development of patient with complete unilateral cleft lip and palate.