IGFBP-7 plays an important role in the process of human pregnancy. However, it is not found in rats. In previous study, suppression subtractive hybridization (SSH) was utilized to analyse differentially expressed gene between pre-implantation period and implantation period and IGFBP-7 was identified as a gene differentially expressed. Temporo-spatial expression pattern of partial IGFBP-7 cDNA sequence(CDs 531～928 nt, IGFBP-7′) in early pregnancy was detected by Northern blot and in situ hybridization. RT-PCR was used to analyse IGFBP-7′ mRNA expression in multiple tissue and uterus of pseudopregnancy, artificial decidualization and delayed-implantation. Results indicated that IGFBP-7′ mRNA expression level began to increase in the day 5 of pregnancy, the expression level during day 5.5 and 6 is higher than pre-implantation period. IGFBP-7′ mRNA was mainly located in luminal epithelium and gland epithelium. The expression of IGFBP-7′ mRNA have not tissue-specific and was detected in hypothalamus, pituitary, uterus, ovary, heart, liver, spleen, lung, kidney and so on. The expression of IGFBP-7′ mRNA was not significantly different in uterus of pseudopregnancy and artificial decidualization, and significantly increased in the uterus of delayed-implantation. Collectively, these results suggest that IGFBP-7′ expression increase is mainly induced by blastocyst, not decidualization during the window of implantation, which may be beneficial to embryo implantation in the early of pregnancy in rats.