The research was carried out in the laboratories of food science department at Faculty of Agriculture, Damascus University during the year 2012 to compare some chemical parameters (moisture،ash, sugars, fat, fibe, protein) and biological active compounds (total phenols, vitamin C) in fresh strawberry fruits and strawberry jam. Statistical analysis showed a significant reduction (p<0.05) in moisture, ash, fat and protein in strawperry jam comparing to fresh fruits. Total phenols was decreased significantly (P< 0.05) from 2078 mg/100 g DM in fresh strawberries to 1070 and 962 mg /100 g DM in homemade and commercial strawberry jam respectively. Also the amount of vitamine c was decreased from 346 mg /100 gram dry matter in fresh fruits to 45 mg/100 gram dry matter in locall made jam ،while it was 30 mg/ 100 gram dry matter in commercial strawberry jam. These were reflected on anthocyanins which was decreased from 1080 mg/ 100 g DM during processing to 132 and 105 mg/ 100 g DM in homemade jam and commercial strawberry jam respectively. These changes reflected in a significant (P< 0.05) decline in the antioxidant activity.