The purposes of this study are stated as follows: 1. to learn physiological reaction in meditation practice. 2. to learn the effect of meditation on child's attention. The study would be 2 (mediator v.s. non-meditator) * 2(pretest vs. posttest) mixed design. The dependent variables would be 1. physiological reactions, e.g., EEG, skin conductance. 2. attention. Subjects are forty-four 4-grade students, which are divided evenly into a meditator group and non-meditator group. The meditator group would attend a 4-day intensive meditation practice. The nonmeditator group, as a control group, did not receive any training. The instruments used in this study are : 1. computerized bio-feedback system, which is used to measure physical reaction. 2. NTU attention test , which is used to measure attention. It was found that after meditation training, the meditation group shows:1. partly different in EEG from control group. 2. significantly low skin conductance than control group. 3. no difference in a attention test from control group. However, in further analysis that separated all subjects into highattention group and low-attention group by their pre-test scores in the attention test. It shows that : 1. in high-attention group, after meditation practice, the meditator-group has significant improvement in their attention ability than the control-group. 2. in lowattention group, there is no significant difference between the meditator group and non-meditator group after meditation.