With both of monopoly mobile and fixed line sectors having terminated in 2001 and 2013 respectively, it implied that CTM will face unprecedented challenges in future. This research aims to assess the fixed line service quality of CTM and provides recommendations to improve its service quality. This research contains both quantitative and qualitative research. The SERVQUAL model developed by Parasuraman, Ziethaml & Berry in1985 has been adopted, associated with descriptive statistics and reliability analysis to conduct this project. Data were gathered via interviews with seven CTM management members and the SERVQUAL survey from 300 CTM customers and 100 CTM staffs from the period of April 2012 to December 2012. Based on the result, it showed that the respondents are not satisfied with the overall fixed line service quality of CTM. Respondents rated that the reliability was the most important service feature of a telecommunications company. However, the mean score of reliability dimension just barely above the average. Moreover, the result of management interview also showed that specification gap (Gap 2), delivery gap (Gap 3) and communication gap (Gap 4) existed between the customers’ perception and CTM management toward the service quality. This project provides an insight of an important telecommunications company in ii Macao. It suggests that CTM should pay more attention to the service quality improvement through narrowing both internal and external gap in order to enhance its competitiveness to compete with new players from market liberalization. The recommendations for service quality improvement are also offered to CTM management for improving its overall service quality and enhancing customer satisfaction to lead to success in the competitive telecommunications industry.