In China, the university-school partnership (USP) is a community of continuous professional development (PD) for teachers, involving teacher educators who visit schools. This study explores teachers' personal factors, school working conditions, and principal leadership in order to explain differences in teachers' learning when they have participated in the training program. Using a one-group pretest-posttest design, 375 teachers from 12 primary schools in Shanghai participated. Their learning performances are measured by changes in their teaching quality as evaluated by their students. Results of regression analyses show that teachers generally receive higher scores on teaching quality after the program than before. Three factors are significantly and negatively related to the changes in quality: teachers' educational level, the extent to which teachers feel emotional pressure in their profession, and the support from their school principal. Implications for school leaders and policymakers are discussed.