Objective: This study investigates the psychometrics of school readiness checklist for preschool children in approaches to learning domain. Method: The checklist was run on a sample of 1193 preschool girls and boys (1022 normal and 171 with mental retardation) who had been recruited on the basis of random cluster sampling. Then the checklist administered for them. Results: Reliability coefficients by internal consistency (Cronbach’s Alpha) of subtests are 0.96, 0.95, 0.95, 0.96, 0.95 respectively for first to fifth subtest. In the differential validity there is meaningful differences between mean marks for normal and mental retarded preschool students (p<0.001). Conclusion: The results showed that reliability and validity of all subtests were high and they could be used to assess achievement readiness of preschool children in approaches to learning domain.