Previous studies have established that practicing of Chinese calligraphy handwriting (PCCH) has consequences on reducing negative emotions (e.g. anxiety) and serve as a supplemental treatment for mental illness (See Kao et al., 2006, 2011 for a review). However, little is known about the relation between the PCCH and positive emotion. The present study investigates whether PCCH has positive effect on emotional states and emotional regulation skills, which serve as core aspects of mental health. A longitudinal developmental design was employed in the present study: 170 primary school students were tested two times across a two-school-year interval, i.e., the beginning of Grade 3 to the end of Grade 4. During the interval, 101 students (experimental group) joined a Chinese calligraphy course which held 2 times per week (approximately 1.5 hours a time) plus extra exercises, whereas another 69 students (control group) did not participant the course. Chinese version of Positive and negative affect scale for Children (PANAS-C) and Child version of the Cognitive Emotion Regulation Questionnaire (CERQ-k) were used to test children’s emotional states and emotional regulation skills in groups (30~40 participants per group) respectively. When controlling positive emotion measured by PANAS-C in the pretest (experimental group: M = 51.91, SD = 11.13; control group: M = 51.82, SD = 12.32), analysis of covariance showed that experimental group’s showed significantly more positive emotions (M = 53.90, SD = 10.80) than control group (M = 50.81, SD = 9.66) in the posttest, F(1,167) = 4.03，p < .05; however, no difference was found in negative emotions with similar analysis (F < 1). More importantly, using change scores (posttest – pretest) on each components of the CERQ-k, experimental group showed significantly more positive changes than control group on two components: positive refocusing (t(168) = 1.99 , p < .05) and refocus on planning (t(168) = 2.20, p < .05). These results suggested that PCCH can have positive effect on the development of emotional states and emotional regulation skills.