The "integrated time-space" perspective of life in traditional Chinese medicine holds that structure and function respectively belong to the realms of space and time. The orderly integration of time and space not only supports the existence and development of life， but also serves as the foundation for biological evolution. Based on this standpoint， this paper proposes the spatiotemporal structural theory of visceral manifestation， characterized by the fusion of time and space， the integration of internal and external dimensions， and the absence of primary or secondary distinctions. Using the individual human body as the boundary， it delineates the man and nature spatiotemporal structure， based on the theory of the "correspondence between man and nature"， and the internal spatiotemporal structure of the living body. The man and nature spatiotemporal structure， with yin-yang and the five phases as its core， reveals the correspondence and connectivity between the external environment and the internal zang-fu organs within the spatiotemporal dimension. The internal temporal structure of the body refers to the collective physiological rhythms related to the zang-fu organs， while the spatial structure refers to the tangible forms， spatial positions， and connective structures of the zang-fu organs. The proposal of the spatiotemporal structural theory of visceral manifestation represents a rational reconstruction and practical exploration of the essential connotations of visceral manifestation， aiming to provide new perspectives for subsequent theoretical research and clinical applications.

Objective To discuss the electrocardiogram(EKG)positioning method to the guiding role of determining the pipe length and the accuracy of operative localization in central venous catheterization procedure. Methods Chose 32 cases of tumor patients who had center venipunture.Use the catheter taken EKG data when cath-etering,and then given validation using postoperative chest X -ray or fluoroscopy.Judgment the sensitivity,specificity and disposable catheters success rate of the EKG positioning method.Results In the 32 cases of cancer patients, 30 patients had characteristic P waves,when the chest X -ray confirmed the superior vena cava or the junction with the right atrium,one case into the right atrium,when one case of non -P -wave in the subclavian after intravenous discounts tune into the tube after it confirmed the superior vena cava.Conclusion EKG positioning method with high accuracy in the deep venous catheter in the catheter tip positioning applications.The clinical applications are feasible.