1-Cheese Composition Data in Table (1) clearly showed that pH of all cheese decreased significantly during storage period. The decrease in the first month in pH was higher than that occur in the second month of pickling Abdou et al (2003) and El Abd et al (2003). LS and LZ cheeses had significantly lower pH compared with L cheese. The pH of full-fat Domiati F cheese was lower than of the low-fat Domiati L cheeses during cheese ripening. Similar results have been obtained by Volikakis et al. 2004, Katsiari and Voutsinas 1994 and Tareq Alnemr 2017. Table (1) also showed a significant decrease (P < 0.05) in moisture content (P < 0.05)of cheese during cheese ripening (Kaya 2002; Melilli et al. 2005; Khosrowshahi et al. 2006; Madadloua et al. 2007; Sadowska et al. 2009). There was a difference (P < 0.05) in the moisture content of the cheeses as a result of adding fat replacers (Table 1). Low fat cheeses made with the whey-based replacers (LS) or carbohydrate-based fat replacers (LZ) had higher moisture contents, respectively, than did the control cheese. This agrees with the observations of Luvey and Gony (12). The low fat cheeses contained the lowest moisture. This may be due to the high water holding capacity of both fat and fat replacers, Ayat 2016 monira 2017 and Tareq Alnemr 2017. There is a significant increase in total nitrogen content (TN) of low fat cheese( L ,LS and LZ cheeses) (P < 0.05) (Table 1). These results are in agreement with the literature (Madadloua et al. 2007;Korish and Abd Elhamid 2012, Philipp Schenkel et al 2013, Tareq Al -Nemr et al 2016 „Ayat 2016 and Tareq Al -Nemr et al 2017 Monira 2017 ). These differences in protein content between the full-fat Domiati cheese and low-fat Domiati cheeses may be attributed to their moisture content. Korish and Abd Elhamid 2012 Abeer 2013) cheeses made by full-fat milk or low-fat milk with fat replacer were within the normal composition range for Domiati cheese (Kebary et al. 2006; Ayad 2009 Treq El -Nemer et al 2016 and Ayat 2016 ). Table (1): Chemical properties of low fat Domiati cheeses. TREATMENTS * F LS LZ Item Months 2 2 1. PH 5.8 4.9 4.4 6.0 5.2 4.5 5.5 4.5 4.0 5.1 4.2 3.8 Moisture % 62.6 58.2 55.3 58.5 52.4 7.2 64.2 60.6 17.5 55.6 66.9 63.3 59.1 F/DM % 46.9 46.5 46.1 15.7 16.9 18.4 16.2 7.9 19.9 16.4 18.6 20.5 T.N/DM% F: Full fat cheese (control), L: Low fat cheese, 6.1 5.8 5.5 7.7 6.8 6.2 6.6 6.1 7.8 6.5 6.0 LS: Low fat cheese with simplesse resemble and LZ: Low fat cheese with Z-trim resemble