The measurements of cardiac systolic duration (SD) and diastolic duration (DD) have been well accepted as helpful tools for evaluating the cardiac functionality. In clinical practice, SD and DD are generally measured using echocardiography or heart sound signals. Recent studies have seen the attempts of approximating SD and DD by electrocardiogram (ECG) derived QT and TQ intervals, as well as radial artery pressure (RAP) derived foot-to-notch and notch-to-foot intervals. However, to the best of knowledge, there lacks deep elucidations on their performance when used as surrogate SD and DD data. We investigated the RAP-derived SD, DD, and ratio of SD to DD (S/D), to heart rate (HR) and age in healthy adults. Sixty healthy subjects were enrolled and their ECG and RAP signals were simultaneously recorded. The SD and DD were extracted automatically from RAP with the aid of the acceleration RAP. The HR was calculated using the RR interval extracted from ECG. Their mean values of 10 cardiac cycles were used in the analysis. Results demonstrated a negative linear relationship between SD and HR, a negative nonlinear relationship between DD and HR, and a positive linear relationship between S/D and HR (all p < 0.001). In addition, age did not suggest statistically significant relation with those RAP derived parameters. Our results were in common with previous publications, confirming that the RAP derived foot-to-notch and notch-to-foot intervals are good surrogates for the cardiac systolic and diastolic durations.