In recent Years the Ethnic Culture Tourism has developed on the fast lane. Though its economic prominence has earned much praise, its cultural authenticity was challenged. To evaluating its culture authenticity, it cannot only stay in qualitative analysis. The quantitative research methods should be combined with scientific evaluation. Basing on the deep understanding of the authenticity of ethnic cultural tourism and using factor analysis, the evaluation system of ethnic cultural authenticity has built up from subjective and objective aspects. It includes six basic indicators. Then it takes Hei Yi Zhuang as an example to inspect such evaluation system.