Gastrointestinal nematode infections cause great morbidity and mortality for the millions of people worldwide, and serious economic losses in live stock farming. Many chemical compounds and plant metabolites have toxic effects on nematode parasites. Synthetic drugs have been considered the most efficient way to control and treat parasite infections. But these drugs are expensive and sometimes unavailable for people and show some side effects which has limited the achievement of gastrointestinal nematodiasis control in sheep. Therefore, in recent years there has been an increasing interest in medical plants as an alternative anthelmintic source. The aim of this research were the investigation of the influence of the mixture of clover (Trifolium pretense L.) and liquorice (Liquorice procera) to the internal organs of the sheep. For this purpose, the sheep were separated into the groups were given at increasing therapeutic dose of the plant mix (grass, clover and liquorice) as twice, three times and five times. The therapeutic dose of the clover and liquorice didn’t cause pathological alterations in the organs (kidney, heart and liver) at the level of the cells and tissue.