The presence of weeds in rice field can cause crop losses until 87%. The rice cultivation system effect on the abundance and diversity of weeds, so the identification of weed species in rice fields is important because to determine weed control strategies. This study aims to identify weed diversity, weed abundance, and weed control strategies in organic and conventional rice fields. The field survey was conducted in Kebonagung Village, Imogiri District, Bantul, Yogyakarta in five plots of organic and conventional rice fields. Weed sampling was collected purposively using the quadratic method in five observation plots (50 cm x 50 cm). Weed samples were taken three times starting from the generative phase. The results showed that abundance and weed diversity in organic and conventional rice fields were not significantly different. Organic paddy fields we are dominated by weeds of Sphenoclea zeylanica and Leptochloa chinensisi L., whereas in conventional paddy fields we are dominated by Sphenoclea zeylanica, Leptochloa chinensisi L., Ludwigia adscendin L. and Pistia stratiotes L. The different types of weeds dominated in organic and conventional rice field are caused by cultivation systems, especially irrigation techniques. So that the control strategy in the organic and conventional rice field can be done by the management of irrigation water techniques.