Objective To assess the correlation between PICC tip shift and the increase of weight, height, upper arm length, chest circumference in the very low birth weight (VLBW) infants, and to establish PICC position prediction method． Methods A total of 42 VLBW infants were enrolled, and their weight, height, arm length, mid-upper arm circumference and chest circumference were measured at the day of catheter placement and one month later. The position of PICC tip was identified one month after catheter placement by X-ray, and multiple linear regression was applied to analyze the factors influencing the tip movement. Results The PICC tip displacement occurred in 95.2% VLBW infants. There was no significant difference regarding the PICC tip shift between different puncture sites（P>0.05）. Regression analysis revealed a relation between the PICC tip shift and upper arm length growth rate (P<0.01). With an increase of 1% of upper arm length, the tip moved 0.15 vertebral bodies away from the heart. Conclusion The upper arm length growth rate is a predictor of PICC tip shift in VLBW infants, so it can be used as a good indicator predicting the position of PICC tip.