Objective To evaluate the feasibility of quantitative evaluation of fallopian tubes patency by the rising slope of pressure curve produced by bolus injection using a liquid diagnostic apparatus in the four-dimen-sional hysterosalpingo-contrast sonography. Methods A total of 205 patients with infertility were collected for four-dimensional hysterosalpingo-contrast sonography. In the examination,the contrast medium concentration,the liquid volume of the liquid diagnostic apparatus and the speed of the liquid were stationary calculated. The rising slope of the curve was calculated according to the real-time pressure curve produced by the contrast agent injection process. According to the hysterosalpingo-contrast sonography examination's results ,patients were divided into one side patency group,one side partial obstruction group and one side obstruction group. The correlation between the slope and the patency of the fallopian tube was analyzed by binary logistic regression. Results Binary logistic regression showed that the slope and fallopian tube patency had good correlation(all P < 0.05)between one side patency group and one side obstruction group,and also between one side partial obstruction group and one side obstruction group;but had no correlation between one side patency group and one side partial obstruction group(regression coefficient P>0.05,regression constant P=0.000). Conclusion The slope of pressure curve produced by four-dimensional hysterosalpingo-contrast sonography can be used to assess the patency of fallopian tubes quantitatively. It is a new auxiliary index for evaluating the patency of fallopian tubes.