An ecological study or rodents was carried out in the different habitat patches of Entoto NaturalrnPark, northern outskirts of Addis Ababa, from February 1998 to January 1999. Twelve speciesrnwere found comprising the rodent fauna of the park. A total of 572 individual rodents belongingrnto nine species werc captured li'OI11 two 0.36 ha grids using a mark-release-recapture technique.rnThe species werc Arl'icall/liis abyssinicus (57%), Myomys albipes (15.73%), Lophuromysrn.flavopunc/alus (7.17%), Mus mahomel (5.8%), Olomys 1)'lJUS (5.24%), Muriculus imberbisrn(4.9%), De.â€¢IIIOIIIYS Ii({rrillglolli (2.27%), Delldmlllus IOl'ali (1.75%) and D. mystaca/is (0.17%)rntogether with the subterranean mole rat (TachyOl)'clcs .jJlendel1.). Presence of two other rodentrnspecies (RollllS mIlliS and l-lys/rix crista/a) was confirmed from survey trapping and indicesrnlike droppings and spines.rnBoth temporal and spatial differences in species number were apparent. Species number on therntwo grids fluctuated between five in the wet season and eight during the dry season and 'smallrnrains'. Disappearance or the small-sized and rarc specics of rodents accounts for the lowerrnnumber of species in the wet season and subsequent months. The number of species of rodentsrnsampled using survey trapping was half of that obtained on the grids.rnMonthly numbers of small rodents that are known to be alive on both grids varied between 93rnat the end or the wet season (October) and 172 during the 'small rains' (April). Population sizernpeaks on both grids appeared during the 'small rains' and in the middle part of the first half ofrnthe dry scason.rnReproductive peaks occurred mainly during and immediately after both the 'small and bigrnrains'. A. ohyssinicl/s, M. o/hipes, and M. illlbcrbis had their reproductive peaks after the 'big'rnand 'small rains'. Loplilll'OIIIYS jlavoplIJ1c/a/lis and o./)11I1S on the other hand had theirrnreproductive peaks during the 'big rains'. Hence, reproductive peaks were associated withrnprecipitation be it 'big' or â€¢small'.rnAdults dominated monthly population structures. Juveniles and subadults were betterrnrepresented in captures made after the main breeding season of each species. More juvenilernL. f1avojJIIIICi((l/Is and 0. i.l'jJlIS were seen just after the end of the wet season while those of A.rnAbyssilliclI.1 and M. iI/hipes were seen two months later.rnThc wet season survival rate was thc lowest for most of the species. Very few members ofrnsome populations survived for II months and the more common species had about 37%rnsurvival probability for three months.rnDistribution of small rodents in habitats and microhabitats of the mountain was patchy andrnrelated to occupation of suitable places. Shrubby grasslands, bushes on brook bank and sloppyrnhillsides were places of high species number. Swampy grasslands, eucalyptus plantation andrngrazed woodlands had none or the least species number of small rodents. Man-madernmicrohabitats like stone fcnce line and hcaped stones together with bushy fragments andrnherbaccous grassland hosted the greatest number of spccies and individuals on the grids. Traprnstations with very short grass and located on sloppy hillsides, rocky out crops and adjacentrneucalyptus plantations had the least species number and capture success.