Abstract: The present invention relates to injections for ocular tissues containing a conjugate covalently bonded a drug to PEG. When the drug-PEG conjugate is injected into the ocular tissues, the drug can be retained in the ocular tissues such as an iris, a ciliary body, a vitreous body, a retina and an optic nerve for a long period. Accordingly, the injections for ocular tissues of the present invention make it possible to treat or prevent diseases m various ocular tissues over a long period by a single administration. PEG can be any of straight-chain, stellate and branched. In the case of straight-chain PEG, since the drugs are generally bonded using hydroxyl groups at its both ends, a binding ratio of the drug to PEG is 1:1 or 2:1. Since stellate and branched PEGs have plural hydroxyl groups, plural covalent bond of drugs to PEG can be formed.