Purpose: To examine thoroughly (1) The effect of Prior Knowledge, Emotional Intelligence and Motivation on Mathematical Communication, (2) The effect Prior Knowledge and Motivation concomitantly on Mathematical Communication, (3) The effect of Emotional Intelligence and Motivation simultaneously on Mathematical Communication, (4) The effect of Prior Knowledge, Emotional Intelligence and Motivation at the same time on Mathematical Communication. Methodology: This observation rendered as quantitative with correlational designed observation. The Applied technical data analysis was descriptive statistic, regressive analysis and coefficient multi-correlation with SPSS. Findings: The findings of this study were to unfold: (1) Positive and significant effect of Prior Knowledge on Mathematical Communication, was the highest effect. (2) Positive and significant effect of Motivation on Mathematical Communication is the lowest effect. (3) Positive and significant effect of Prior Knowledge and Motivation concomitantly was higher effect than Emotional Intelligence and Motivation on Mathematical Communication. (4) Positive and Significant effects of Prior Knowledge, Emotional Intelligence, and Motivation simultaneously effected on Mathematical Communication. Significance: In virtue of the findings result, herewith the researcher proposed a recommendation to the teachers so that always being paying attention upon the three independent variables in time of ongoing learning mathematics because of these three variables when they are maximized at the same time will reinforce Mathematical Communication maximally. To the next researcher may do research concerning motivational consequence to become the least contributor to Mathematical Communication as had been retained in this observation.