Abstract: Pure parental three lines of Iran silkworm has been individual recording and forty best male and female individual selected in each of these parental three lines. Then these lines has fed according conditions of lines increasing system of Line lines, parent-parent and silkworm mother and during three successive generations, silkworm egg each of three lines 32, 104 and 110 generated without performance of new selection. For each of line formed two groups (random parents group and selective parents group) in each of line compared each other performance of two groups and analyzed obtained result of individual selection system of parental lines on the performance of these lines. In this project used of present on records in Iran silkworm research center that are relative to actions and performances of this system and had taken 2000-2003 during successive for years. In this study, tools of record and data collection were standard form of economical characters recording in the silkworm and Excel software and for statistical analysis is used method of Generalized Lined Models (GLM), SAS software edition 6.12. Studied characteristics were generation characteristics, pupae characteristics, larval duration and cocoon weight. Pupae vitality percentage (middle cocoon) in three lines 32, 104 and 110 was for selective groups 85.091, 91.001, 88.012% and for random groups 91.258, 82.450, 88.107%, respectively. Produced in cocoon number in three lines 32, 104 and 110 was for selective groups 213.63, 263.42, 282.42 and for random groups 247.96, 240.46, 243.91, respectively. Total best cocoon weight in three lines 32, 104 and 110 was for selective groups 372.77, 324.80, 295.86 g and for random groups 308.00, 298.51, 236.96 g, respectively. Hatched larvae number in three lines 32, 104 and 110 was for selective groups 588.92, 500.33, 561.83 and for random groups 520.25, 503.54, 489.74, respectively. Un-hatched egg number in three lines 32, 104 and 110 was for selective groups 18.958, 20.750, 7.458 and for random groups 11.958, 25.083, 13.826, respectively. Total produced egg number in three line 32, 104 and 110 was for selective group 617.17, 532.50, 582.46 and for random groups 551.46, 541.38, 522.22, respectively. These characters had included more significant in relation to other studied characters in this study and respond positive to selection. With due, attention to in each line there is significant difference in response to selection so the selection can cause to increase economical characters performance in silkworm.