Manliness and masculinity are two related and different concepts, and there have been inaccurate rendering into Chinese and confusing usage, but there has little study of the distinction between them in domestic academic circle. The paper sets out to distinguish the two terms from the perspectives of philosophy, anthropology, sociology and culturology, in hope of distinguishing them in terms of their etymological and cultural development, their definition, scope and criteria, their value orientation and judgment, and their construction strategies and modes of practice. The paper aims at redressing the misconceptions about manliness and shedding light on the predicaments of modern masculinity, and it also proposes reconstructing contemporary manliness.