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decays of a bound state of a quark and its anti - quark , quarkonium , provide an excellent laboratory for studying qcd . particularly , heavy quarkonia such as charmonium states are less relativistic , thus play a special role in probing strong interactions . cleo recently has accumulated data taken at the @xmath5 resonance , providing a total of 27 m @xmath5 decays . with the combination of this large statistical sample and the excellent cleo detector , we will explore an unprecedented world of charmonia . while many analyses are currently being carried out , in this note we present recent results on multi - body @xmath0 decays which employed the pre - existing 3 m @xmath5 sample . we also present recent studies on decays of one of the exotic states , y(4260 ) , as well as precision measurement on @xmath2 that has an implication on properties of x(3872 ) .    finally , based on the full sample of @xmath5 data , we have results on properties of one of the light mesons , @xmath6 . @xmath7 states , which have one unit of orbital angular momentum and total spin of j=0 , 1 , or 2 , can not be produced directly from @xmath8 collisions . they can be reached from @xmath5 through radiative ( electric dipole ) transitions . since @xmath9 , and @xmath10 for j=0 , 1 , and 2 respectively @xcite , 27 m @xmath5 decays of the new data provides @xmath112 m decays of each spin state of @xmath0 which should give us a greater understanding of the decay mechanisms of the @xmath0 mesons .    in this section , we present recent results of studies of @xmath0 decays based on 3 m @xmath5 decays which should serve as the foundation for the future precision measurements by employing the full data sample of 27 m of @xmath5 decays . we present results on @xmath0 decay into combinations of @xmath6 and @xmath12 mesons . figure  [ fig : etaetamass ] shows invariant masses of combinations of @xmath6 and @xmath12 . no @xmath13 is seen as expected from conservation of spin - parity . ( a ) , @xmath14 ( b ) , and @xmath15 ( c),width=302 ]    we measured @xmath16 to be @xmath17  @xcite where the first uncertainty is statistical , the second is systematic , and the third is systematic due to the uncertainty in @xmath18 . this is slightly higher , but consistent with , the two previously published measurements . the bes collaboration measured this branching ratio to be @xmath19  @xcite and the e-835 collaboration  @xcite had @xmath20 . we also measured @xmath21 to be @xmath22 for the first time . we set upper limits for @xmath23 , @xmath24 , @xmath25 , and @xmath26 at @xmath27 confidence level . our result can be compared to predictions based on the model of qiang zhao  @xcite . he translates these decay rates into a qcd parameter , @xmath28 , which is the ratio of doubly- to singly - ozi suppressed decay diagrams . in his model , our results indicate that the singly - ozi suppressed diagram dominates in these decays . we have also looked at three - body decays of @xmath0 states ( one neutral and 2 charged hadrons )  @xcite . they are @xmath29 , @xmath30 , @xmath31 , @xmath32 , @xmath33 , @xmath34 , @xmath35 , and @xmath36 . measured branching fractions are summarized in table  [ tab:3btab ] . again , our results are consistent with the results from bes collaboration  @xcite , with better precision .    in three of the above modes we looked for , @xmath29 , @xmath33 , and @xmath35 , we observed significant signals of @xmath13 decays which are shown in figure  [ fig : threebody ] . [ cols="<,^,^,^",options="header " , ]     [ tab : etabr ]    further more , we also measured the mass of @xmath6 meson  @xcite . this was motivated by two recent precision measurements that were inconsistent with each other . in 2002 , the na48 collaboration reported @xmath37  mev  @xcite , while in 2005 , gem collaboration reported @xmath38  mev  @xcite which was 8 standard deviations below na48 s result . we used the same @xmath6 sample described previously in this section but used only 4 decay modes , @xmath39 , @xmath40 , @xmath41 , and @xmath42 while , again , constraining masses of @xmath43 and @xmath5 . our result , the average of the 4 @xmath6 decay modes , is @xmath44  mev which has comparable precision to both na48 and gem results , but is consistent with the former and 6.5 standard deviations larger than the later . we note that the kloe collaboration also recently measured mass of the @xmath6 meson to be @xmath45  mev which was presented at the 2007 lepton - photon conference  @xcite . i have presented confirmation of babar s observation of y(4260 ) in di - pion transition to @xmath43 along with a new observation through neutral di - pion transition . our precision measurement on @xmath2 calls for more precise measurement on @xmath46 . with 3 m @xmath5 sample , we have results on two- , three- , and four - body decays of @xmath0 states in which many sub - structures were seen in three- and four - body modes . dalitz plot analyses were done for the case of 3-body decays . more detailed analyses can be done with the full 27 m @xmath5 sample . using the 27 m sample , we performed precision measurements on @xmath4 and @xmath3 . 99 w. m. yao _ [ particle data group ] , j. phys . g * 33 * , 1 ( 2006 ) . g. s. adams _ et al . _ ( cleo collaboration ) , phys . rev . d * 75 * , 071101(r ) ( 2007 ) . 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recent results on charmonium decays are reviewed which includes two- , three- and four - body decays of @xmath0 states , observations of y(4260 ) through @xmath1 transitions , precise measurements of @xmath2 , @xmath3 as well as @xmath4 .