This research aimed: 1) to blended learning activities Management by Inquiry Cooperative with lesson package in Research Subject for Learning with an efficiency criteria of 80/80, 2) to compare students’ learning achievement between before and after learning through blended learning activities by inquiry cooperative, and 3) to study students’ satisfactions towards blended learning activities by inquiry cooperative with lesson package. The research samples were 37 early childhood undergraduate students in academic year 2019, Santapol College. The samples were selected by cluster random sampling method. The instruments consisted of: 1) Programed instruction research subject for Learning Development. 2) Lesson plans of research subject for learning development. 3) Learning achievement test, the difficulty index was 0.38-0.80, the discriminated Index was 0.22-0.82, the reliability is 0.89 and 4) the questionnaire of the assessment for satisfaction with five rating scale. The statistics used for analyzing the data were percentage, mean, standard deviation and t-test Dependent Sample. The findings of this research revealed as follows: 1) The efficiency of blended learning activities by inquiry cooperative group with lesson package in research subject for learning development was at 84.89/82.77 level which was higher than set criteria. 2) The students who studied blended learning activities by inquiry cooperative had a higher learning achievement and the level of significance was at .05 And 3) Students were satisfied with blended learning activities by inquiry cooperative was at the ‘much’ level in overall ( =4.47, S.D.=0.24).