Alkaline body conditioning for pregnancy is not reliable. The pH of the human body is in a relatively constant range, the normal human PH value fluctuates between 7.35-7.45. The homeostasis of the human body fluid environment is the prerequisite and guarantee for maintaining normal metabolism and physiological functions of the human body. If the PH value is lower than the normal range, it is acidosis; higher than the normal range is alkalosis. Normal human body can through the respiration and kidney metabolism, so that the PH value in a relatively stable state. The human body does not exist the concept of acidic and alkaline body, and can not be adjusted to achieve the purpose of acidic or alkaline body. Alkalizing the body to prepare for pregnancy is obviously not reliable. Preparation for pregnancy still needs balanced and comprehensive nutrition, moderate physical exercise, quit smoking and drinking, keep in a good mood, and at the same time, if necessary, visit an obstetrician and gynecologist to receive scientific guidance on preparation for pregnancy.