Abstract: Objective　To survey and analyze the routine reference intervals of peripheral blood determination among healthy children. Methods　A total of 2 408 healthy children from 2 to 6 years old were classified into several groups (2-，3-，4- and 5-)，and the white blood cell，red blood cell，hemoglobin，hematocrit，mean corpuscular volume， mean corpuscular hemoglobin， mean corpuscular hemoglobin concentration of peripheral blood were determined. Reference intervals were obtained by statistical analysis of the parameters among the different age groups. Results　Among the different age groups， the white blood cell was statistically significant (P<0.05). However， separate reference intervals were not estimated, unless the difference was at least 25% between the subclass means and combination means. The other parameters had no statistical significance (P>0.05). After the combination of the above parameters， the interval of white blood cell was 4.8-11.6(7.7) ×10⁹/L， the interval of red blood cell was 3.75-5.18(4.47)×10¹²/L， the interval of hemoglobin was 110-145(126)g/L， the interval of hematocrit was 31.2-41.5(36.3)%， the interval of mean corpuscular volume was 76-88(81)fL， the interval of mean corpuscular hemoglobin was 25-31(28)pg， the interval of mean corpuscular hemoglobin concentration was 329368(349)g/L，and the interval of platelet was 175-460(310)×10⁹/L. The reference intervals of hemoglobin, red blood cell and hematocrit in Shanghai were similar to those in Changsha，and were lower than those in Kunming. The low and high limits of platelet in Shanghai were higher than those in Changsha and Kunming. Conclusions　Different detection system should be established for the reference intervals in the different regions and different laboratories.

Key words: Reference interval, Blood routine test, Peripheral blood, Children