Relationship among three point selection methods based on the midnight-noon ebb-flow theory, namely Najia fa (day- prescription of acupoints), Nazi fa (hour-prescription of acupoints) and Yangzi Shike Zhuxue fa (point-open method based on the mother and son relation as well as the hours and its divisions), were approved in the article, which provided the scientific validity of the correlation among three point selection methods of midnight-noon ebb-flow theory.Electric impedance on relevant acupoints of 30 health subjects on the period of the day of Zishi (from 11:00 p.m. to 1:00 a.m.), Maoshi (from 5:00 a.m. to 7:00 a.m.), Wushi (from 11:00 a.m. to 1:00 p.m.) and Youshi (from 5:00 p.m. to 7:00 p.m.) were tested with NQ-1B conductivity meter. And statistical analysis was made on the testing results.The daily average value of the method of Najia fa in 1 circle of the midnight-noon ebb-flow theory was 0.459omega, the value of the method of Nazi fa was 0.553omega, and the Yangzi Shike Zhuxue fa was 0.533omega. At the same time, it presented a tendency of first raising and then declining from Zishi to Youshi with the peak appears at Maoshi and the valley at Youshi. The differences of comparison of the average electric impedance between Najia fa and Nazi fa, Najia fa and Yangzi Shike Zhuxue fa were considered statistical significant (both P < 0.001). When 2 values of different methods within the same hours were compared, the value difference between Najia fa and Nazi fa in the time period of Wushi and the difference between Najia fa and Yangzi Shike Zhuxue fa in the time period of Wushi were considered statistical significant (P < 0.001, P < 0.01).The changing tendency of electric impedance of different point selection methods based on midnight-noon ebb-flow theory is similar, however, with weak relevance. Moreover, obvious differences can still be found in point location and time selection.