In order to process and preserve vegetables by High Pressure Processing (HPP), the texture and tissue of celery processed by HPP was studied in this paper. HPP is gaining in popularity with the world food industry. However, processing and preservation of vegetables by HPP is an advanced technology. In this study, ten celery samples had been treated at the diverse pressure for different time respectively. Furthermore, the slices of the samples before and after HPP had been made and observed by microscope. Although little celery juice effused at ultra high pressure (600 MPa) for 5 min or at 400 MPa for longer time (more than 20 min), the comprehensive observations and analyses showed that in general the texture and tissue of celery could not be damaged by high pressure. The conclusion is that processing celery at 600 MPa for 5 min is the practicable technology.