A　series　of　novel　conjugates　between　1-[4-(2-carboxyethyl)phenoxy]　zinc(II)　phthalocyanine　(1)　and　two　kinds　of　molecular-weight　chitosan　oligosaccharides　(COS1　and　COS2)　or　their　quaternized　derivatives　(QCOS1　and　QCOS2)　have　been　prepared　and　characterized.　Their　photophysical　and　photochemical　properties,　cellular　uptake　and　in　vitro　photodynamic　antifungal　activity　against　Candida　albicans　have　also　been　investigated.　The　conjugates,　1-COS1　and　1-COS2,　exhibit　excellent　photodynamic　inactivation　capacity　(IC90~10　μM),　while　the　quaternized　conjugates,　1-QCOS1　and　1-QCOS2,　due　to　their　less　aggregation　in　aqueous　media,　higher　singlet　oxygen　generation　efficiency　and　cell　uptake,　achieve　higher　antifungal　phototoxicity　(IC90~5　μM).　The　COS　molecular　weight　has　no　obvious　effect　on　the　antifungal　activity.　All　of　the　conjugates　are　far　superior　to　compound　1,　which　can　be　ascribed　to　the　fact　that　the　introduction　of　COS　and　QCOS　onto　phthalocyanine　molecules　can　lessen　their　aggregation　behavior,　enhance　their　singlet　oxygen　generation　efficiency　and　increase　their　cell　uptake　in　aqueous　media.　More　interestingly,　quaternized　conjugates　show　special　affinity　to　the　mitochondria　of　C.　albicans　and　may　induce　apoptosis　upon　illumination.　These　results　suggest　that　the　quaternized　conjugates,　1-QCOS1　and　1-QCOS2,　are　potential　candidates　for　photodynamic　antifungal　therapy.　©　2018　Elsevier　Ltd