Blueberry contains substance natural anthocyanin color that is high enough from the skin to the flesh. Anthocyanin is substance that have a role giving red, blue, and purple and has the potential to be a natural dye to see dental plaque. The material that is often used to see the plaque is disclosing solution. The purpose of this study was to determine the effectiveness of blueberry concentrate (Vaccinium corymbosum) as an indicator of plaque on students of Pondok Pesantren Sarochaniyah Meteseh Semarang in 2017. The research method used in this research is Quasi Experimental Research. The research design used in this research is Posttest Only Control Group Design. The sample used were 60 students for respondent's measurement of color, taste and color concentration from blueberry concentrate and disclosing solution, while to know plaque index was divided into 2 groups. Group 1 of 30 santri were treated with blueberry concentrate, and group 2 was treated with disclosing solution. The results showed that there was a difference in mean plaque index between blueberry concentrate with disclosing solution was 1.7 and 2.5. The difference in the pleasures of the blueberry concentrate is 32 and to the comfortable feeling of disclosing solution is 28. In concentration the concentrated color of the blueberry concentrate is 21 and at concentrated discolouration the color concentration is 39. This indicates that the blueberry juice is less effective to use as an indicator plaque.