In order to analyzing the distribution pattern of seedlings of P. euphratica after river overflowing, Clark-Evans index was calculated for measuring the distribution pattern by using the nearest neighbor analysis method and tested the deviation of actual CE index from the 1 by using the standard normal distribution. The results indicated that: (1) In the quatrats of 3m?3m, seedlings of P. euphratica presented aggregated distribution after river overflowing for 0-1 year and 1-2 year, uniform distribution after river overflowing for 2-3 year, and random distribution after river overflowing for 4-5 year and 5-7 year. (2) With the growth of P. euphratica’s age, the special distribution pattern of seedlings of P. euphratica changed from aggregated distribution to uniform distribution and to random distribution finally in the quatrats of 3m?3m. (3) In the various sizes of quatrats of 2?2 m to 10?10 m, seedlings of P. euphratica presented random distribution after river overflowing for different year. And the test value of standard normal distribution show that the deviation of CE value of P. euphratica seedlings from 1 in the various sizes of quatrats were not significant. As the scale increase, the spatial distribution pattern of P. euphratica seedlings had no significant change, and they always presented random distribution pattern.