PURPOSE: To provide an antitumor agent containing a specified hydrocortisone analog as the active component, low in toxicity and glucocorticoid effect, capable of high dosege administration over a long period and excellent in vascularization inhibition.

CONSTITUTION: The objective antitumor agent contains a hydrocortisone analog represented by formula by formula I (R1 is H or F; R3 is H in the case of R2 is hydroxyl or a carbonyl is formed by R2 and R3; R4 is H or methyl; X and Y are each H or form a C-C single bond in combination), In addition, the compound of formula I can be obtained by reacting a compound of formula II with dihydropyrane in the presence of an acid catalyst such as p- toluenesulfonic acid.