Lithium titanate whiske($Li_{x}Ti_{4}O_9$) was prepared by an ion-exchange reaction. To this end, the initial material, potassium tetratitanate ($K_{2}Ti_{4}O_9{cdot}nH_{2}O$) was prepared by calcination of a mixture of $K_{2}CO_3;and;TiO_2$ with a molar ratio of 2.8 at $1050^{circ}C$ for 3 h, followed by boiling water treatment of the calcined products for 10 h. Fibrous potassium tetratitanate could be transformed into layered hydrous titanium dioxide ($H_{2}Ti_{4}O_9{cdot}nH_{2}O$) through an exchange of $K^{+};with;H^{+}$ using 0.075 M HCl. Also, lithium titanate whisker was finally prepared as $Li^{+};and;H^{+}$ ions were exchanged by adding 20 mL of a mixture solution of LiOH and $LiNO_3$ to 1g whisker and stirring for $5~15$ days. The average length and diameter of the $Li_{x}Ti_{4}O_9$ whiskers were $10~20{mu}m;and;1~3{mu}m$, respectively.