Purpose: This study aimed at examining the psychometric properties of the Assessing Quality Teaching Rubric (AQTR) that was designed to assess in-service teachers' quality levels of teaching practices in daily lessons. Methods: 45 physical education lessons taught by nine physical education teachers to students in grades K-5 were videotaped. They were all Caucasians (5 females and 4 males) with their teaching experience ranging from 6 years to over 20 years. Four investigators coded the taped lessons using AQTR assessment sheet. Results: The total scale and the four sub-scales of the AQTR had satisfactory Cronbach's alpha coefficients. The results of t-test and the MANOVA revealed that the AQTR was a valid instrument to differentiate quality levels of the Overall Quality Teaching, Task Design, Task Presentation, Management, and Instructional Response among each teacher, and between the above-average and the below-average groups. The confirmatory factor analysis further confirmed the establishment of the construct validity of the AQTR. Conclusions: The AQTR was a reliable and valid measure that can be used to assess in-service teachers' quality levels of teaching practices.