To study the effect of PD I administration on dopamine receptors (DR1, DR2 ) mRNAs expression in the lesioned striatum of the PD rat model and confirm if PD I has the effect of dopamine receptor agonist. The PD rats with unilateral 6-hydroxydopamine lesioned were administrated with PD I , L-dopa methyl/benserazide, L-dopa methyl/benserazide/ PD I , normal saline respectively for 4 weeks and their behavioral changes were observed. Then the rats were sacrificed and RT-PCR technique was used to detect changes of dopamine receptors (DR1, DR2 ) mRNAs expression in the ipsilateral striatum 1 day after the last treatment. The results showed that treatment with PD I plus L-dopa resulted in a stable contralateral rotation behavior; treatment with L-dopa resulted in a progressively increased contralateral rotation behavior. Rotation behavior induced by anhydromorphine decreased with PD I or PD I plus L-dopa treatment. Treatment With L-dopa or PD I plus L-dopa, up-regulation of DR1 mRNA and down regulation of DR2 mRNA were observed in the ipsilateral striatum which were more obvious than that treated with PD I or vehicle (P＜0.05). It was concluded that long-term treatment with PD I could alleviate the behavior of PD rats.PD I had no apparent effect on the dopamine receptors (DR1 , DR2) mRNAs expression in the ipsilateral striatum and the PD I has no agonist effect on dopamine receptors.