Structural control methods are aimed to decrease structural responses and improve the dynamic behavior against lateral loads such as wind or earthquake. These methods are classified to three main category of passive, semi active and active. Semi active control possesses both adjustability of active control and reliability of passive control. Semi active control needs a small power source such that lack of electricity during earthquakes cannot disturb its function. In this study a tuned liquid damper (TLD) with baffles is used. TLD is a damper with low installation and maintenance costs and can simultaneously be utilized as a water tank. The used TLD has 4 baffles in two rows that can rotate during excitation. The semi active control algorithm is implemented using the optimal linear control method with time delay compensation. Four far fields and four near field earthquake record are used to study effects of baffles’ rotation. Results show that semi active TLD improves structural behavior more than passive one. Also, the performance of semi active TLD under near field earthquakes are better than that under far field earthquakes.