This research is intended to determine whether or not there is a correlation between reasoning ability and diction competence and cognitive ability to analyze aspects of writing either separately or simultaneously. The correlational research was conducted from September to November 1994. The population was the students of the Indonesian Language and Literature Education Department of the Faculties of Teacher Training and Education Sebelas Maret University and Muhammadiyah University in Surakarta who had taken Writing. and the sample was 60 students taken using proportional random sampling technique. The data -which were the score of achievement of the three variables above were collected through tests. Based on the result of try out the instruments were proved to heve an acceptable validity and reliability i.e. the reasoning ability test (r .925) diction competence test (r .888) and cognitive ability to analyze applied here was the technique of regression and correlation. The result of analysis showed that there was a positive correlation between reasoning ability and cognitive ability to analyze aspects of writing diction competence and cognitive ability to analyze aspects of writing and between reasoning ability and diction competence together and cognitive ability to analyze aspects of writing.