Polycrystalline bulk samples Zn0.98Fe0.02O doped with additional Sn or Cu have been fabricated at 600oC by a coprecipitation method. The XRD structure analysis shows that all samples are of single phase with the ZnO-like wurtzite structure. X-ray photoelectron spectroscopy indicates an oxidation state of 4 for Sn，while a mixed state of 1 and 2 for Cu. It is found that Zn0.98Fe0.02O without additional doping shows weak ferromagnetism at room temperature. Cu doping has induced a light increase of magnetization in low temperature of 10 K, while Sn doping has seriously suppressed the ferromagnetism in whole temperature range. This result is consistent with bound magnetic polaron model relative to hole carriers.