Sequential determination of Ti(III) and Ti(IV) is proposed using a FI manifold. A mixture (standard/sample) of Ti(III) and Ti(IV) is injected into a stream of acidic Fe(III) solution whereby redox taking place before merging into a thiocyanate stream. Ti(III) reduces Fe(III). The intensity of the colored Fe(III)-thiocyanate complex then decrease and monitored continuously at 450 nm. The decrease will be related to the amount of Ti(III). By switch a three-way value for a stream of hydrogen peroxide, another injection of the mixture will allow Ti(III) to be converted into Ti(IV). Ti(IV) (both the converted one and the Ti(IV) in the original mixture) forms a yellow complex with hydrogen peroxide. The signal will correspond to the total Ti. By difference, the amount of Ti(IV) can be evaluated. Optimization of the system will be discussed.