Nanomedicine is extensively explored for cancer therapy, aiming to improve drug efficacy and toxicity by delivering drug molecules more efficiently to pathological sites and reducing accumulation in healthy organs. Over 20 cancer nanomedicines are approved for clinical use, with hundreds in development. Key challenges include biological barriers and pathophysiological heterogeneity, beyond materials and production issues. The article discusses principles, progress, and products in nanomedicine tumor targeting, current problems, and future prospects. Cancer therapy involves surgery, radiotherapy, chemotherapy, and other modalities. Anticancer drugs often fail due to poor tumor targeting and severe side effects. To improve therapeutic index, various drug delivery systems, including liposomes, polymers, and nanomaterials, have been developed. These include antibody-drug conjugates (ADCs) and nucleic acid delivery systems like lipid nanoparticles. Passive tumor targeting relies on the enhanced permeability and retention (EPR) effect, which is influenced by tumor vascular characteristics. However, tumor heterogeneity and pathophysiological differences challenge EPR-based targeting. Strategies like ultrasound and microbubbles can enhance tumor perfusion and penetration. Active targeting uses recognition motifs to bind to cancer cell receptors, improving drug delivery to target cells. ADCs, such as Kadcyla and Enhertu, are effective for HER2-positive cancers. Nanomedicines include liposomes, polymeric micelles, and inorganic nanoparticles. Approved products include Doxil, Abraxane, and Genexol-PM. These formulations aim to reduce side effects and improve drug targeting. Recent developments include ThermoDox, a temperature-responsive liposome, and polymeric micelles for multi-drug delivery. Challenges include heterogeneity in tumor physiology, lack of biomarkers for patient stratification, and difficulties in clinical translation. ADCs offer advantages like intrinsic biomarker targeting, while nanomedicines require better biomarkers and strategies for effective targeting. Future directions include improving targeting efficiency, developing new platforms, and enhancing clinical translation through biomarker-driven approaches.Nanomedicine is extensively explored for cancer therapy, aiming to improve drug efficacy and toxicity by delivering drug molecules more efficiently to pathological sites and reducing accumulation in healthy organs. Over 20 cancer nanomedicines are approved for clinical use, with hundreds in development. Key challenges include biological barriers and pathophysiological heterogeneity, beyond materials and production issues. The article discusses principles, progress, and products in nanomedicine tumor targeting, current problems, and future prospects. Cancer therapy involves surgery, radiotherapy, chemotherapy, and other modalities. Anticancer drugs often fail due to poor tumor targeting and severe side effects. To improve therapeutic index, various drug delivery systems, including liposomes, polymers, and nanomaterials, have been developed. These include antibody-drug conjugates (ADCs) and nucleic acid delivery systems like lipid nanoparticles. Passive tumor targeting relies on the enhanced permeability and retention (EPR) effect, which is influenced by tumor vascular characteristics. However, tumor heterogeneity and pathophysiological differences challenge EPR-based targeting. Strategies like ultrasound and microbubbles can enhance tumor perfusion and penetration. Active targeting uses recognition motifs to bind to cancer cell receptors, improving drug delivery to target cells. ADCs, such as Kadcyla and Enhertu, are effective for HER2-positive cancers. Nanomedicines include liposomes, polymeric micelles, and inorganic nanoparticles. Approved products include Doxil, Abraxane, and Genexol-PM. These formulations aim to reduce side effects and improve drug targeting. Recent developments include ThermoDox, a temperature-responsive liposome, and polymeric micelles for multi-drug delivery. Challenges include heterogeneity in tumor physiology, lack of biomarkers for patient stratification, and difficulties in clinical translation. ADCs offer advantages like intrinsic biomarker targeting, while nanomedicines require better biomarkers and strategies for effective targeting. Future directions include improving targeting efficiency, developing new platforms, and enhancing clinical translation through biomarker-driven approaches.