This study aimed to identify the psychological hardness and its relation with the Quality of life among Postgraduate Students in Nizwa University. The sample of the study Consisted of 362 students; 199 meles and 163 females. The sample were Chosen based on the stratification random method. In order to achieve the aims of the study the descriptive correlational approach was used. The researcher used two tools: the psychological Hardiness scale prepared by (Mikhamar, 2006) and improved by (AL abdali,2012), and the quality of life scale prepared by (Mansi and Kazim, 2006). The study Findings show the following: 1. Psychological hardness level among Postgraduate Students in Nizwa University according to the total sum of the scale was high. 2. Quality of life level among Postgraduate Students in Nizwa University according to total sum of scale was middling. 3. No statistically significant difference at the indication level (0.05 > a) for the psychological hardness level according to Gender. 4. No statistically significant difference at the indication level (0.05 > a) for the psychological hardness level according to GPA. 5. There are statistically significant difference at the indication level (0.05 > a) for the quality of life level according to Gender, for females. 6. No statistically significant difference at the indication level (0.05 > a) for the quality of life level according to GPA. 7. There is an extrusive statistically significant relation between psychological hardness level and quality of life level among Postgraduate Students in Nizwa University. 8. Psychological hardness helps in predicting quality of life among Postgraduate Students in Nizwa University.