The results of a Russian national study of the quality of preschool education (2016-2017, N[subscript kindergartens]= 1,301) are discussed with a focus on possible predictors of quality dynamics on the relations between Early Childhood Environment Rating Scale--Revised scores and group size, number of teachers in a group, child/adult ratio, teachers' qualifications and working experience, and enrollment of teachers into in-service training. The child/adult ratio was found to be a stronger predictor of process quality than the group size and the number of teachers. No connection was revealed between process quality and teachers' age and working experience. The impact of in-service training depends on the evidence-based orientation.