The purpose of this study was to investigate the effects of scientific program for gifted elementary students using metacognition on learning-flow and lingual interaction. For the purpose, the two classes for elementary science of P Institute for Gifted Education located in Pusan were assigned to experimental and control groups, respectively. The experimental and controls groups received eight sessions applying a program for scientifically gifted students using metacognition and same program without using it, respectively. The learning-flow test and the lingual interaction observed among students and between teacher and students pre and post program were compared and analyzed. The results shows that there was no significant difference between pretest and posttest in experimental group, indicating that learning-flow is not a construct obtained by short-term using of metacognition. For the lingual interactions, however, the amounts of conversation and the ratio of high level conversation in experimental group were 1.6 and 1.5 times higher than those in control group. This suggests that the lingual interaction may be varied among classes even with same experiments, by instruction method. The lingual interaction is not active in control group where the experimental results may be obtained easily only with sincere attitude while, in experimental group, questions using metacognition and providing intellectual stimulation is continuously presented, leading to high level of lingual interaction, therefore it is considered that the development of scientific program for gifted elementary students using these advantages is needed.