[Objective] The aim was to explore the morphological characteristics of ovum from Spodoptera exigua and Heliothis assulta.[Method]The ultra morphological characteristics of ovum was observed with scanning electron microscope（SEM）.[Result]The ova from S.exigua and H.assulta are all spheroid,the former has net line decoration on surface,with some aeropyle distributed on the net line decoration;the micropyle is located in the center of polar and has plum flower-like engraving;the surface of chorion of the latter has the parallel crowns through two polar.Between the parallel crown,the surface of chorion has the decorated trapezium line,all crowns of second polar zone have breast-tuber that distributes in parallel at the same latitude in line,and there is no aeropyle distributing on chorion.[Conclusion] The ultra morphological characteristics of the ova from two Noctuidae species showed significant difference to each other,which enriched ontogenesis data and also provided reference for the accurate identification of two kinds of ova.
