In this paper, we propose a line-field optical coherence tomography (OCT) with frequency-sweeping source, which uses imaging optics to form a line focus on the sample and obtains cross-sectional OCT images of biological tissues without any mechanical scanning. Therefore, real-time imaging becomes possible even when the sweeping rate of the source is not high. Moreover, a full 3-D volume image can be acquired by simply incorporating 1-D mechanical scanning. Our line-field OCT using frequency-sweeping source has a sensitivity of ~88 dB, an axial resolution of 8.3 mum, and an acquisition speed of 45 fps.