The delta-endotoxin genes of Bacillus thuringiensis (Bt) and proteinase inhibitor (PI) genes are two kinds of genes popularly used for developing transgenic plants resistant to pests. A series of feeding experiments was conducted to determine the effects of pollen from transgenic cotton (cv. SGK321) and maize crops containing cry1Ac, cry1A+CpTI or cry1Ab genes, as well as pollen from non-transgenic normal cotton (cv. Shiyuan321) and maize, on the growth and development as well as cocoon quality of Bombyx mori. The pollen from non-transgenic plants had no significant adverse effects on larval mortality, cocoon weight, pupal weight, cocoon shell weight, pupation rate, emergence rate and fecundity of silkworm after neonates were fed with the pollen for 72 h. In addition, no dosage effects of pollen were found. Though the duration of 1st instar larvae was prolonged in the case of feeding with transgenic pollen as compared with those of the non-pollen treatment, they were not significantly different from those fed with pollen from non-transgenic cotton or maize. Meanwhile, the body weight of the 3rd instar molters fed with transgenic pollen was significantly heavier than that of the controls. Consequently, it is considered that pollen from transgenic insect-resistant cotton and maize has negligible adverse effects on the growth and development of the silkworm.