According to areas where blackberries are grown, world leaders are Europe and North America. Some of the major European manufacturers are Hungary, the United Kingdom, Romania, Poland and Germany. Cultivation of blackberry in the Republic of Croatia is still not at satisfactory level. Advantages of growing blackberry are it's early ripening (in the second year of cultivation), high and stable yields ( up to 30 tons per hectare ), the fruit rich in vitamins and minerals, the flower of blackberry is excellent bee pasture. Untoward feature of growing blackberry is tedious vintage whereas that blackberries do not ripen at the same time so harvest sometimes lasts for forty days. Although there are machines that make harvesting easier, human labor is indispensable. By doing this research I wanted to show how production systems ( organic and integrated ) have an effect on some pomological and chemical properties of the fruit of blackberries. Two cultivars that are often present in production in Croatia have been studied, thonfree and boysen cultivars. The aim of this research was to determine the differences in width , length and weight of the blackberry fruit and the concentration of solids , sugar , total acid and vitamin C in blackberry fruit in relation to the system of production and cultivar. Measurements of the width of the fruit show that the highest average value measured is for cultivar Boysen in organic production ( 19.7 mm ) , while the lowest is for cultivar Thornfree also in organic production ( 17.6 mm ). The average length of the fruit ranged from 24.1 mm to 26.4 mm. The average length of the fruit in the integrated production amounted to 24.75 mm , and 26.15 mm in the ecological production. Average value of the length of the fruit are higher for cultivar Boysen ( 25.9 mm) than of the cultivar Thornfree ( 25.0 mm ). The average fruit weight ranged from 4.01 g to 5.60 g. The average fruit weight for cultivar Boysen is 5.57 g, and variety Thornfree 4.02 g . The differences between the integrated and organic production less ( 4785 g / 4805 g ) . The average fruit weight ranged from 1.4 g do 5.60g . The average fruit weight for cultivar Boysen is 5.57 g , and for cultivar Thornfree 4.02 g . The difference between the integrated and organic production is not large ( 4785 g / 4805 g ). According to chemical composition of blackberries we come to following conclusions, content of dry matter in fruit of Thornfree cultivar (average of cultivar 19.57%) is higher than in the cultivar Boysen (average of cultivar 16.26%), this feature was not affected by production system. The pH value is slightly higher for the organically produced blackberries (2.74) from those grown by integrated production (2,60), while the average pH value of the cultivar Boysen is lower (2.45) than the cultivar Thornfree (2,90). Average of total sugar content was slightly lower in integrated production (7.85%), than in organic (8.25%), and the the difference among cultivars (Boysen 6.88%, Thornfree 9.23%) is larger. ivar Boysen is lower (2.45) than the cultivar Thornfree (2,90). Average of total sugar content was slightly lower in integrated production (7.85%), than in organic (8.25%), and the the difference among cultivars (Boysen 6.88%, Thornfree 9.23%) is larger. Absolutely lowest total acidity was measured for cultivar Boysen in integrated production in amount to 1.73%, while the highest acidity measured for cultivar Thornfree in organic production amounts to 1.96%, and the trends are the same as for the content of total sugars. The concentration of vitamin C in blackberry fruits in the test ranged from 17.26 till 20.05 mg / 100 g fresh weight.