Host sex plays many different roles in maintaining the genetic diversity of parasitoids and hence their evolutionary potential. However, less studies have evaluated the effect of host sex on biological properties of parasitoid up to now. Parasitoid wasp of Venturia canescens (Gravenhorst) (Hym.: Ichneumonidae) is one of the important natural enemies of Pyralidae family which attacks the larval stage. In the present study, the effect of host sex (male or female) on the percentage of larval parasitism and also on the weight of adult wasp were studied under laboratory conditions. The test was performed at 25±1°C, relative humidity of 60±10% and 16: 8 L: D periods. Twenty numbers of host, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae), in their last larval stage were placed inside the cylindrical containers (180× 80 mm) for freshly removal wasps. These wasps were fed with 10% honey water solution. After 24 hours, wasps were taken out of the experimental containers. Factors were evaluated in the completely randomized design with 15 replications for each sex of host (male and female). Our final results showed that there was a significant difference between treatments (P<0.05; F= 4.83), in which the highest percentage of parasitism occurred on female host larvae (61.5%). Significant difference was not observed between the weight of wasps which were exited from male or female host larvae (P=0.539; F= 0.39). These finding is an empirical evidence that shows any host sex can affect the biological properties of parasitoid. Pest control optimization is the important result of these finding.