Targeted　tumor　imaging　and　efficient　specific　gene　delivery　in　vivo　has　been　one　of　the　main　challenges　in　gene-based　cancer　diagnosis　and　therapy.　Herein,　we　engineered　a　citric　acid-based　polymer　with　intrinsical　photoluminescence　and　gene　loading　capacity　to　achieve　targeted　delivery　of　siRNA　and　tumor　imaging　in　vitro　and　in　vivo.　The　multifunctional　platform　was　formed　from　the　self-assembling　of　poly　(citric　acid)-polymine　conjugated　with　folic　acid　and　rhodamine　B　(PPFR).　PPFR　showed　stable　photoluminescent　ability　and　could　effectively　bind　and　protect　the　siRNA　against　RNase　degradation.　PPFR　also　exhibited　good　blood　compatibility　and　cell　compatibility　against　C2C12,　MCF-7　and　A549.　Compared　with　commercial　transfection　agent　Lipofectamine™　2000,　PPFR　had　a　high　cellular　uptake,　equivalent　transfection　efficiency　and　effectively　down-regulated　intracellular　p65　expression　in　A549　cancer　cells.　Importantly,　PPFR　could　efficiently　accumulate　and　label　the　tumor　tissue　through　the　fluorescent　imaging,　selectively　deliver　siRNA　into　tumor　tissue　in　vivo　based　on　the　tumor-bearing　nude　mice　model.　This　work　may　provide　a　facile　strategy　to　synthesize　multifunctional　biocompatible　biomaterials　for　targeted　tumor　imaging　and　gene　therapy.