The clinical efficacy of ultrafine traditional chinese veterinary medicine Chicken Coccidia Powder（CCP）was studied in this trial. The trial chickens were artificially infected coccidiosis by Nanchang strain of chicken E.tenella and then treated according to the design. The 240 test Isa cockerel of the same age, same weight were selected and divided into eight groups, three samples each group, 10 repeated per sample, and the Anticoccidial Index（ACI） was used as a index for therapeutic efficacy.The ACI of the negative control group（no insect attack, without medication）, the positive control group（insect attack, without medication）, fine CCP group（1% fine CCP feeding,about 300 mesh）, the Diclazuril group（5 μg/g Diclazuril feeding）, low-dose ultrafine CCP group（0.5% ultrafine CCP feeding, about 1 000 mesh, the same below）, high-dose ultrafine CCP group（1% ultrafine CCP feeding）, lowdose combination of ultrafine CCP and Diclazuril group（0.5% ultrafine CCP + 2.5 μg/g Diclazuril feeding） and high-dose combination of ultrafine CCP and Diclazuril groups（1% ultrafine CCP + 2.5 μg/g Diclazuril feeding）were 200.00, 88.73, 146.45, 178.28, 143.99, 160.82, 170.31 and 188.04, respectively. In six treatment groups, the high-dose combination of ultrafine CCP and Diclazuril groups was the efficient（ACI≥180）. The Diclazuril group,high-dose ultrafine CCP group and low-dose combination of ultrafine CCP and Diclazuril group were in effect（ACI = 160 ～ 179）, fine CCP group and low-dose ultrafine CCP group was low efficient（ACI ＜160）. The results showed that ultrafine traditional chinese veterinary medicine can improve efficacy after ultrafine grinding, and they combined with chemical veterinary medicine not only could enhance the efficacy, but also reduced the amount of chemical veterinary medicine.