Study of ππ production in two-photon collisions at Belle

We have measured the cross section forπ~+π~- production in two-photon collisions using a data sample with an integrated luminosity of 85.9 fbcollected with the Belle detector.The fo(980)resonance is observed as a peak in the energy spectrum of the cross section.We also report preliminary results forγγ→π~0π~0 with two-photon center-of-mass energies ranging from 0.6 to 4.0 GeV,based on a 95 fbdata sample.We find at least four resonant structures including a peak from f(980).In addition,there is evidence forχO production.We also make a preliminary discussion of the angular dependence and cross section ratio ofγγ→π~+π~- andγγ→π~0π~0.