With phase-plane analysis in Matlab, the relations between the bacterial indicators and dissolved oxygen (DO), pH and temperature, was examined by considering the dynamic during 20 September 2013 to 8 February 2014 for water quality monitoring in enclosed coastal waters at the edge of the Kas region of Turkey. It has been suggested that the bacterial indicator phase plane analysis provides a good method of monitoring. It was shown that temperature (significance value, p=4.9e-05), DO (p=1.0e-04) and pH (p=4.6e-04) values have a significant effect on bacterial indicators. The relationship between the bacterial indicators was examined by comparing the same scale "cusp" diagrams, and it was demonstrated that total coliforms concentration were closely related with faecal coliforms (FC) concentration. In presenting the enclosed coastal water quality information, weighting average water quality index (WQIMP) has been used by selecting the sets of appropriate parameters. To keep track of and analyse changes over time by calculating the index numbers, the set of seven variables which are FC, DO, pH, temperature, turbidity, nitrate, total suspended solids and the set of three variables which are FC, temperature, DO were utilized successfully (p=8.3e-05). Parameter quality values were obtained from the software developed using cubic hermite polynomial in Matlab.