The aim of this study was assess the therapeutic effect of targeted intra-arterial verapamil infusion in liver cancer patients and its side-effects in a dog model. The blood verapamil levels in dogs were determined after one-off intra-arterial infusion (0.7 mg/kg). Blood pressure, breathing state, and II-lead electrocardiogram were measured. Primary liver cancer patients (100) were randomly assigned into two groups. Controls (50) were treated with targeted intra-arterial infusion, and every patient received once-a-month interventional therapy, twice. Treatment group (50) received chemotherapeutics plus verapamil. Therapeutic and toxic side effects were evaluated. Control (41) and treatment group (45) patients were further treated with a second round of targeted intra-arterial infusion of chemotherapeutics plus verapamil, in 30 days after the 2-time interventional therapy. Every patient accepted interventional therapy 4-5 times during the 6 months after the first confirmed diagnosis. Following verapamil infusion, verapamil in dog liver was tenfold higher than in blood and was 4- to 20-fold higher than that needed for reversing carcinoma drug resistance. After interventional therapy, there were no significant changes in iconographic evaluation indices between the groups. Average activities of aminotransferases were 332 and 178 U/l in the treatment and control groups (P < 0.05). The imaging parameters of the treatment group were significantly better than those of control group. No side effects were found among the 91 patients who accepted verapamil infusion. After verapamil infusion, verapamil levels in dog hepatic tissue exceeded the effective concentration that reverses carcinoma multidrug resistance without any visible changes in the vital signs. Targeted intra-arterial verapamil infusion could improve the chemotherapy for the primary liver cancer patients without any side effects.