Background : Hyperglycosylated hCG a newly discovered variant of hCG which can be used as a predictor of invasion of trophoblastic cells in patient with gestational trophoblastic disease. Objectives : To measure hyperglycosylated human chorionic gonadotrophin and to assess how far it can be used as predictor of invasion in invasive mole and choriocarcinoma. Study design control study. Setting: : Case Gynecological department in Baghdad Teaching Hospital from January 2016 to January 2017. Patient and Methods : 60 women were enrolled in this study 30 of them were with gestational trophoblastic disease (no.= 30 ) the remainder were normal pregnancy (no. =30) , hCG –H level was measured in both groups. Results : Mean serum hCG-H level was significantly higher in patients with gestational trophoblastic disease compared to control women (460.5 ± 168.35 , 206.8± 19.99 ) respectively with p value < 0.05. Mean serum hCG-H level was significantly higher in patients with gestational trophoblastic disease Invasive mole and chriocarcinoma compared to patient with molar pregnancy. Before evacuation (772.11 ± 184.08, 398.27 ±65.86). After evacuation (550.52 ± 146.15 , 340.40 ±85.61). With p value < 0.05. Conclusion : 1) Serum hCG-H level was higher in patients who had invasive mole and patients with choriocarcinoma than patients with gestational trophoblastic disease , so it can be used as a predictor of invasion in patients with invasive mole and choriocarcinoma. 2) Serum hCG-H level can be used in patient with abnormal β- hCG after evacuation when it is slowly decreasing or plateau. 3) It is better to measure the ratio hCG-H/total hCG and using uniform method test and units so we can understand the actual changes that happen in invasion.