Abstract : The process of platelet storage lesion during the storage of thrombocyte concentrate (TC) blood components can have an impact on platelet viability and decreased hemostatic function. This study analyzed the effect of storage time for TC blood components on beta thrombomodulin levels, platelet count, and mean platelet volume (MPV). This type of research is an analytical study with a time-series design. Sampling was done by consecutive sampling. A sample of 25 TC bags was freshly made and stored at room temperature with agitation in the Blood Bank of Dr Soetomo Hospital. Examination of beta thrombomodulin levels, platelet count, and MPV was performed to assess platelet storage lesion on day 1, day 3, and day 5. Data were analyzed using the Shapiro-Wilk test, Kruskal Wallis test, Bonferroni test, and Games Howell. There is a change in beta thromboglobulin levels, on day 1 the mean rank (32.5), day the 3rd (32,20), day 5th (49.24) and MPV, on day number 1 average (7,744 fL), day 3 (7,928 fL), day 5 (8,248 fL). There was no significant change in the platelet count on day 1 (mean (210,200 / uL), day 3 (192,485) /uL), 5th day (214.201 /uL). There was no decrease in the number of platelets on storage days 1, 3, and 5 so the TC component was still feasible to be given to patients, even though there were changes in beta thrombomodulin and MPV. Further research is needed for other parameters that can be affected by the storage process.