Echoes of the Heart comprises 193 poems grouped under 125 titles in four chapters. The first chapter, "Musings and Inspirations," enounces, in a classical poetic tongue, his thoughts upon nature and human development, rules of personal conduct and moral cultivation, and the wisdom and rationales behind various ways of doing things. In the second chapter, "Family Bliss and Camaraderie," Ma Kai lets his love for his parents, wife, daughter and grandsons flow like a springtime stream, and tells about his friendship with friends and colleagues. The third chapter, "The Vicissitudes," gives expression to the poet's abiding loyalty to his motherland and his people as he relates his observations of and perspectives upon some of the major events that he has personally experienced at home and abroad. The fourth chapter, "Scenes and Sights," presents a fabulous tapestry of the landscape of China, with the author's love for nature and life embroidered in between the lines of his poetry.

《心声集》选收了马凯先生125题193首诗作，共分四篇。第一篇为"感悟篇"，反映了作者用诗的形式对自然界和人类发展，对怎样做人、如何做事的思考；第二篇为"寄情篇"，抒发了作者对父母、妻子、女儿、孙子和朋友、同事的亲情、爱情、友情；第三篇为"沧桑篇"，记录了作者亲身经历的发生在中国大地上的一些事件，表达了作者对祖国、对人民的赤子之心；第四篇为"揽胜篇"，描绘了祖国的大好河山，反映了作者对自然、对生活的热爱之情。