Abstract: OBJECTIVE To investigate the preventive effect of aloe gel on doxorubicin-induced extravasation injury and the underlying mechanism. METHODS Sprague-Dawley (SD) mice were used to establish the extravasation injury model induced by doxorubicin. Seventy SD mice were randomly divided into seven groups: non-injured control group, simulated operation group, doxorubicin-induced extravasation injured group, dissolvant control group, hyp-concentration (0.1 g·L^-1) aloe gel protected group, meta-concentration (1.0 g·L^-1) aloe gel protected group, hypsi-concentration (10.0 g·L^-1) aloe gel protected group. The areas of the extravasation injuries were measured to observe the degree of doxorubicin-induced extravasation injury. The pathological morphology was observed by optical microscopy. Expression of basic fibroblast growth factor (bFGF) and intercellular adhesion molecule (ICAM-1) in the exosmosis skin and subcutaneous tissues was detected by immunohistochemistry. RESULTS The areas of extravasation injuries in aloe gel protected groups at different concentration were smaller than that in doxorubicin-induced extravasation injured group (P<0.05). The result of HE stain revealed that the degree of extravasation injuries in aloe gel protected groups at different concentration was obviously less severe than that in doxorubicin-induced extravasation injured group. The result of immunohistochemistry revealed that the expression level of bFGF was lower and ICAM-1 was higher in doxorubicin-induced extravasation injured group than that in non-injured control group, while the expression level of bFGF was gradually higher and ICAM-1 was gradually lower in aloe gel protected groups at different concentration than that in doxorubicin-induced extravasation injured group, in a dose-dependent manner. CONCLUTION Aloe gel prevents doxorubicin-induced extravasation injury. Its mechanism is related with the up-regulation of bFGF expression and down-regulation of ICAM-1 expression.