A simple, Accurate, precise method was developed for the estimation of the Trilaciclib in bulk and pharmaceutical dosage form. Chromatogram was run through X-bridge (100x 2.1mmx 3.5µm). Mobile phase containing 0.1% OPA: Acetonitrile taken in the ratio 72.2(%v/v) and 27.78 was pumped through column at a flow rate of 0.29 ml/min. Temperature was maintained at 27.5°C. Optimized wavelength selected was ACQUITY TUV ChA 219.0 nm. Retention time of Trilaciclib was found to be 1.757 min. %RSD of the Trilaciclib was found to be 0.2. %Recovery was obtained as 99.85% for Trilaciclib. Regression equation of Trilaciclib is y = 9698x + 2551.2 and correlation coefficient was found to be 0.999. Retention times were decreased and that run time was decreased, so the method developed was simple and economical that can be adopted in regular Quality control test in Industries.