Objective To explore the relationship among derived parameter of pulse length（DPPL）

cyclical variation rate of area（CVRA） of longitudinal section of radial artery and peripheral tissue and pulse length.Methods A new-type sphymograph was applied to collect synchronously the pressure phygmograms of guan pulse

signals of ECG and dynamic B ultrasound images of longitudinal section of radial artery of 40 patients and 20 healthy persons.The effect of different pulse length on DPPL and CVRA was observed based on the digital signal processing and image analysis with MATLAB 7.0.1.Results Compared with those in normal pulse group

DPPL and CVRA of long-variation pulse group and short-variation pulse group were significantly different（P<0.05 or P<0.01）.Compared with those in long-variation pulse group

DPPL and CVRA of short-variation pulse group were significantly decreased（P<0.01）.Conclusion DPPL and CVRA can be used to differentiate the pulse length preliminarily.