Abstract: Marx and Engels' theory of value isn't “monism on the labor theory of value”, but a macro “utility/labor theory of value”. The labor theory of value is only the beginning of advancing from abstraction to concrection. This paper points out that Kautsky's “economical theory of Marx” had written before volume three of “Capital” published, and it has some absolute or formal understandings about volume one “Capital”. Afterward, some people such as Bernstein, according to volume two and three of “Capital”, suggest interconnection between labor theory of value and utility theory of value happened that time, which is in accordance with the truth of the labor theory of value. Some people like Kautsky criticized Bernstein's points by “Monism on the labor theory of value under the banner of “Against Revisionism”. They were wrong in understanding Marx-Engels' theory, though reasonable in politics. The “Monism” became main legacy theory in Lenin, authority in USSR, vestige in China, is left behind by deceased “Platform of Class Struggle” in theory of value.