as possible. According to the animation of Fig.\[fig1\], the cool material went across this place continuously during the period about from 05:10 UT to 08:54 UT and then the filament appeared. On the other hand, the jet was wider than the filament, so the jet’s width would embody the filament. Therefore, the uncertainty in the definition of the boundary between the jet and the filament had only little effect on the estimate of the cross-sectional width of the jets. Fig.\[fig6\] exhibits the time-distance diagram derived by a series of H$\alpha$ images observed by the NVST during the period from 04:48 UT to 09:00 UT. Panels (a)&(b) show the variations of intensities along the slice path, respectively. Using the different intensities along the slice and the maximum of the variation rate nearby the jets’ position, we can approximately identify the two boundaries of the jet plasma to derive the width of the cross-section. For the complex profiles of the slice’s intensity, it need manually identify the boundary. We obtain the $w(t)$ is around 2.75 Mm at 06:07:53 UT, while the $w(t)$ is around 4.01 Mm at 07:30:38 UT. Therefore, based on the time-distance diagram, the $w(t)$ at different moments can be 