We studied the diversity of beetle families in watermelon fields in the palm grove of Zaatote at Ouargla (34? 54' N., 5? 20' E.). The sampling method used was Barber pots as they allowed the largest number of captures of insects, regarding both individuals and species. Over the three years of the study (2016, 2017 and 2018), we identified 787 individuals from 12 taxonomic families. Throughout the sampling period, the Coccinellidae family was clearly dominant, with an Fc% of 35.02 % in 2016, 36.2 % in 2017 and 34.34% in 2018. The second most dominant family was Tenebrionidae with an Fc% of 26.35% in 2016, 30.04% in 2017, and 33.33% in 2018. Other families were poorly represented. In 2016, regarding their trophism, 18 species of beetles (30.91%) were phytophagous and feed on the watermelon crop, while 26 species were predatory and decomposing auxiliaries.