Objectives To explore the health research capacity (HRC) and factors associated with professional and technical personnel (PTP) in a first-class tertiary hospital in northwest China. Methods We collected the repeated measurement data from a first-class tertiary hospital in northwest China between 2013 and 2017. HRC of PTP was assessed by a comprehensive evaluation system and measured by research capacity score (RCS). The participants were divided into research group (RCS >0) and comparison group (RCS = 0); participants of the comparison group were selected by two-stage stratified random sampling. Multilevel model for repeated measures was used to investigate the potential factors associated with HRC. Results A total of 924 PTP were included (308 in the research group and 616 in the comparison group). This study found consistent growth in RCS and associated 95% CIs for the hospital during 2013 and 2017. The linear multilevel model showed PTP with a doctorate degree had higher RCS than those with a master's degree (beta, 1.74;P<0.001), bachelor's degree (beta, 2.02;P <0.001) and others without a degree (beta, 2.32;P<0.001). Furthermore, the PTP with intermediate (beta, 0.13;P = 0.015), vice-high (beta, 0.27;P= 0.001) and senior (beta, 0.63;P<0.001) professional titles had higher RCS than those with junior positions. Compared with PTP in the administration, those in paediatrics had higher RCS (beta, 0.28;P= 0.047) though similar to PTP in other departments. PTP with an administrative position had a higher RCS than those in non-administrative positions (beta, 0.26;P<0.001). The RCS increased with the research fund (beta, 0.15;P<0.001). However, no associations were found between RCS and sex, age, ethnic, graduate school or technical type. Conclusions HRC with associated variation of PTP for the hospital in northwest China increasingly improved and degree, professional title, administrative position, and research fund were related to HRC of PTP. Multi-central prospective studies are needed to clarify the potential relationship of related factors and HRC of PTP.