本研究は、子どもの異文化経験が英語コミュニケーション能力と動機づけへ及ぼす影響を検討した。公立小学校3校の262名(海外滞在経験32名・海外旅行経験132名・海外経験なし98名)を対象に、5年次に英検ジュニア・シルバーテストと動機づけの質問紙調査を行い、1年後に追跡調査をおこなった。本結果から、海外滞在経験は、英語コミュニケーション能力と内発的動機づけを向上させることが分かった。また、海外旅行経験は、内発的動機づけを向上させることが明らかになった。6年次には群別のコミュニケーション能力の影響は変化しないが、異文化経験による内発的動機づけへの影響は消えていた。しかし、同時期の外発的動機づけの変化も考察した結果から、子どもの異文化経験(海外滞在経験・海外旅行経験)は、内発的動機づけを高めることを基盤に、6年次には、英語学習と将来性を繋げる同一視的調整を高め、複数の動機によって動機づけを強化すると結論づけられた。 This study examined the effects of intercultural experiences on English communicative competence and learning motivation of students studying at three public elementary schools in the Kanto region of Japan. The participants of this study were 262 fifth-grade students with and without intercultural experiences. The students were divided into the following groups: those with experience of living overseas (n = 32), those with experience of travel overseas (n = 132), and those with no overseas experience (n = 98). The Eiken Junior Silver Test was administered to the participants to assess their English communicative competence. In order to assess their intrinsic motivation and extrinsic motivation including the constituent regulations (identified, introjected, and external), a questionnaire was administered. The study also included an identical follow-up procedure conducted after one year, when the participants were sixth graders. The results of the study suggest that regardless of school grade, students living overseas for a mean period of two and a half years showed a greater gain in English communicative competence than students without such experience. Specifically, the group of participants who had lived overseas for the abovementioned mean period showed statistically higher mean scores on the Eiken Junior Silver Test than the other two groups. Although an improvement in test scores was recognized from grades five to six in all groups, there was no difference in the mean levels of test score improvement attributable to exposure to intercultural experience. Regarding intrinsic motivation, the findings suggest that in the fifth grade, students with intercultural experiences (living and traveling overseas) had stronger intrinsic motivation as compared to those without such intercultural experiences; however, this difference disappeared in the sixth grade. Thus, it can be inferred that the effects of intercultural experiences on intrinsic motivation do not last long. The effects of intercultural experiences on extrinsic motivation also show that such experiences (living and traveling overseas) increase identified regulation from grades five to six. It can be inferred from this that intercultural experiences ultimately enable students to envisage more clearly how to relate their English learning to their future goals. These results also suggest that intercultural experiences stimulate the development of children, as identified regulation becomes strong after adequate intrinsic motivation is cultivated at an early age. Effects on introjected and external regulations differed based on the extent of the participants’ intercultural experiences. Only the group who had traveled overseas showed an increase in introjected regulation from grades five to six. Thus, it can be inferred that the experience of traveling overseas promotes learners’ self-motivation by leading them to compare their English competence to that of others who have achieved higher levels. This inference is reasonable as the experience of traveling overseas provides high intrinsic motivation similar to that of the living overseas experience, but unlike the latter, it does not increase English competence simultaneously. Regarding external regulation, this study found that the experience of living overseas increased the external regulation from grades five to grade six, whereas the experience of traveling overseas decreased the external regulation in the same period. The difference in these results may be due to differences in the degree to which students are also engaged in supplementary education. Finally, the present study further provides examples of the effects of intercultural experiences on the participants’ English communicative competence and learning motivation from their parents’ viewpoint, using the questionnaire responses of the parents (e.g., concerning what the participants said or did after intercultural experiences). Based on the findings from the responses of the participants and their parents, three implications relating to potential use of the intercultural experiences of students in elementary school English education are discussed.