A compound represented by Formula I or pharmaceutically acceptable salt thereof. The present invention relates to a 4-arylamino quinazoline hydroxamic acid compound having a histone deacetylase inhibitory activity, preparation method of the compound, pharmaceutical composition comprising the compound, and use of the compound and the pharmaceutical composition in the preparation of a histone deacetylase inhibitor medicine. The present invention aims at acquiring, via a medicine design and a synthetic technology, a series of selective histone deacetylase inhibitors having good hypotype selectivity and favorable pharmacokinetic characteristics based on optimization of an enzyme surface recognition region and connection region of 4-arylamino quinazoline, thus reducing an effect on normal tissues or cells while improving an antineoplastic activity of the normal tissues or cells.In Formula I, the variables are as described herein.