This research aims to 1) study the demographic features to the view of the competitive potential in telecommunication business in Bangkok Metropolitan Region totally 4 sale departments and Metropolitan customer service department. 2) study the association of the effectiveness of marketing communication mix and corporate image in order to promote telecommunication business in Bangkok Metropolitan Region totally 4 sale departments and Metropolitan customer service department. 3) study the association of corporate image in order to promote and increase its potential to compete in telecommunication business in Bangkok Metropolitan Region totally 4 sale departments and Metropolitan customer service department. and 4) study the association of the effectiveness of marketing communication mix and competitive potential in telecommunication business in Bangkok Metropolitan Region totally 4 sale departments and Metropolitan customer service department. The Purposive Sampling was selected as a method to figure out a sample group who was the staff of TOT Public Company Limited in Bangkok. Staff’s job position were as follows; 1) Customer Service Center Manager 2) Financial Administrator and 3) Services Administrator 195 persons in total. The data were collected by using the questionnaire which was divided into 5 parts. The first part was the general information of the respondent’s status. The second part was the viewpoint of the marketing communication mix. The third part was the viewpoint of the corporate image in order to promote marketing. The fourth part was the viewpoint of the competitive potential in telecommunication business. And the fifth part was the closed-ended questions of the problem and solutions. This research was using descriptive statistics to analyze such as frequency percentage average SD (Standard Deviation) t-test One way ANOVA and Pearson‘s Correlation Coefficient analysis as hypothesis testing.