The present study were carried out to study the influence of different host plants on some biological characteristics ofcitrus mealybugs Planococcus citri. The experiments were carried out in the laboratory of the Economic Entomology Department, Faculty of Agriculture, Mansoura University under daily fluctuated temperature degrees of 28.4±3.1˚c and R. H. 70±5% on different host plants. The total duration of immature stages (incubation period and nymphal stage) were the shortest when the citrus mealybug P. citri reared on guava followed by ficus and succari orange and represented by 24.7±2.90, 28.7±2.92 and 30.5±3.19 days with significant differences, respectively. Meanwhile, the longest duration of the developmental stages were recorded on mango and grapevine and represented by 32.7±3.41 and 33.7±3.66 days, respectively. According to the survival rates as an index of suitability of different host plants, the suitability in decreasing order was on guava trees (0.78), ficus religiosa (0.74), succari orange (0.64), mango (0.60) and Grapevine (0.53). The longest oviposition period, the longest adult longevity and the highest fecundity for adult females of P. citri  were recorded when reared on guava followed by ficus religiosa and succari orange. Meanwhile the shortest oviposition  period, the shortest adult longevity and the lowest fecundity for adult females of P. citri were recorded when reared on grapevine followed by mango.