Objective: To study the changes of stability, pH, particles and concentrations within 12 h of Ketorolac Tromethamine Injection and Dezocine Injection after mixing dilution of PCIA at room temperature, so as to provide scientific references for clin. Methods: Clarity detector was used to study compatibility solution (1:1) with different temperatures and compatibility solution of PCIA (1:1, 3:1). Meanwhile, particles analyzer, pH meter and HPLC were adopted to determine the changes of pH, particles and relative contents after Ketorolac Tromethamine Injection being mixed with Dezocine Injection (1:1, 3:1) for PCIA. Results: It showed that there were no significant changes in particle, pH and relative content within 12 h after being mixed for PCIA. Conclusion: Particles, pH, visible foreign substance and relative content of compatibility solution (1:1, 3:1) for PCIA remained stable within 12 h. There was no compatibility taboo for both injections.