在五声性音高领域中探索，是作曲家罗忠镕自“创作之初”便确立的创作追求，直至最终形成具有鲜明个人特征的“五声性十二音”理念和音乐语言。对罗忠镕在“创作之初”如何探索做出分析，是更深入研究他音乐创作及其相关问题的起点。文章围绕罗忠镕第一部器乐作品《第一小奏鸣曲》的第一乐章，探讨他“创作之初”的音乐理念及其形成动因，分析他如何以器乐化思维和技法来实践“在五声性音高领域探索”这一创作探索。

Until finally having established his symbolic“pentatonic-dodecaphonic”concept and music language,LUO Zhongrong had always had his initial artistic pursuit in the exploitation of pentatonicism.Analyzing on how Luo explores in his initial compositional period is the point of departure for any further study of his creative issues.This study focuses on his very first instrumental work Sonatina No.1 and discusses how his music idea of this period emerged and how he applies it instrumentally to conduct his exploration in the field of the pentatonicism.