Hospitalization can produce anxiety and interrupt school age children’s wellness. Although many methods have been applied to handle child anxiety, however the most new effective one has not found yet. The art therapy is one of alternatives to minimize child anxiety. This research goal is to describe art therapy effect toward minimizing anxiety in school age children undergoing hospitalization. Quasi experimental research was set on pre-post test non-equivalent control group design. Research population was 6-12 years old children undergoing hospital care at RSUD Prof. Dr. Margono Soekarjo and RSUD Banyumas, and purposive sampling was applied to them. Sample research was 60 children between age 6 and 12 years old, divided into 2 groups. Those were 30 children as research group and 30 children as control group. Child drawing: Hospital (CD: H) instrument was used in this research to measure anxiety. The effects of art therapy were tested with Chi Square. This statistic analyses showed that there was different anxiety level between two groups before applying art therapy (p=0,011). However there was no difference anxiety level between two groups after applying art therapy (p=0,760). An additional analyses showed that art therapy effectively reduce arterial pulse level (p=0,008). There was no evidence that age, length of care, and experiencing care correlate to anxiety level after applying art therapy, except sex in experimental group with anxiety level. Results showed that art therapy did not reduce anxiety level however this was effective in reducing arterial pulses, one of anxieties physiological responses. Developing the research in art therapy need randomize sampling to increase homogeneity between two groups then will strengthen the result. Pediatric nurses should applying art therapy with variation method to reduce anxieties physiological responses.