Hard disk drives (HDD) are now the most important means of information storage, and they continue to be made smaller in size, higher in capacity, and lower in cost. The dynamic performance of an HDD has been an increasingly important consideration for its design, as we move forward toward its consumer applications. The dynamic properties of the head arm assembly (HAA) of a micro-drive were investigated using both experimental and numerical techniques. A finite element model for studying the dynamic property of the HAA was created and modified according to the experimental results. Good correlation between the experimental results and those by finite element simulation was achieved.