Abstract: The mixed coccidia oocysts were collected from local chicken dung of coccidiosis and cultivated to be sporulated. Then the sporulated coccidia oocysts were inoculated to chickens. The caecum coccidia oocysts of inoculated chickens were collected. The single-oocyst isolation technique was used to abtain pure coccidia strain from the caecum coccidia oocysts. After passage propagation through chickens the indexes such as size of oocysts, latent period, sporation time of oocysts, parasitic site were observed and detected. The results showed that the average size of oocysts was （25.743±1.94126）μm×（21.4±1.85985）μm, the oocyst index was 1.2067±0.07, the latent period was 140 h, oocyst discharged peak was the seventh day, the shortest sporlation time was 19h and the coccidium parasitized in chicken caecum. According to above observed and detected materials the separated coccidium was identified to be Eimeria tenella and it was named Eimeria tenella Guangxi Nanning strain (Eimeria tenella-GXNN). This research has set up a foundation for further studying on drug and immunity prevention of chicken coccidiosis.

Key words: chicken; coccidia; separation; identification