PT. Jaya Arnikon is a contractor company which is engaged in the procurement of services for departments which includes construction of multistorey buildings, housing and real estate, highway, irrigation, bridges, and other instruction sectors. PT. Jaya Arnikon always increases of their performance to give satisfaction for their stakeholders. Among others, formal communication and informal communication is very important means to support employees performance, but sometimes there are barriers in communication among employees. One type of barrier in communication is the presence of miss communication. The purpose of this final report was to know every influence of formal communication and informal communication on the performance of employees of PT. Jaya Arnikon. Literature reviews, observation, interviews, and questionnaires were used to collect data.This study uses method of multiple linier regression coefficient analysis. Questionnaires were distributed to 32 employees as respondents. Regression analysis was used to determine the influence of formal communication and informal communication on the performance of employees. Data collection method were processed using SPSS 16.0. The result of this study was that calculation of regression coefficients obtained Y = 1.989 + 0.596X1 – 0.321X2. It meant that result of regression gave influence on the performance of employees, and the coefficient of determination was 0.555. It meant that the employees performance of 55.5% was influenced by formal communication and informal communication. While the rest of 44.5% was influenced by other factors.