Autism affects about 4.57 million children under the age of five worldwide, and 95% of them live in low-and-middle-income countries, where services are scarce. In China, there is a scarcity of professionals who can provide evidence-based treatments. Families of children with autism often experience delays in diagnosis and treatments, and this waiting period could be used for initial parent education and training. This dissertation focused on translating an evidence-based practice (EBP), the Parent-mediated Early Start Denver Model (P-ESDM), into a culturally appropriate telehealth intervention for families with a newly diagnosed child in mainland China. The study aimed to: (1) culturally adapt P-ESDM using the Ecological Validity Model (EVM) and family-centered capacity-building approach, (2) determine the feasibility of conducting a randomized controlled trial of this telehealth intervention in the Chinese context, (3) evaluate the intervention implementation by assessing parents' satisfaction, acceptability, appropriateness, and feasibility, and (4) explore the effectiveness of this telehealth intervention on both children's and parents' outcomes. The first study aimed to report cultural adaptation and feasibility testing. We used EVM to guide the adaptation, and five dimensions were modified: language, person, content, methods, and context. We developed a 12-week telehealth intervention with sixty-three lectures, seventy-five demonstrations, fifty-three commentary videos, eleven practice manuals, and eleven group agendas. A randomized controlled trial (RCT) was conducted with two telehealth conditions: self-directed and web + group therapy. 18 parents in the self-directed condition received intervention individually through the online learning platform. 19 parents in the web + group therapy condition navigated the same program with weekly 1.5-hour group coaching sessions via videoconferencing. The trial presented promising feasibility results in recruitment capability, retention, parental adherence, and participation. High rates of attendance and completion were observed in the treatment group. The second study adopted a convergent mixed-methods design to evaluate intervention implementation based on the conceptual framework of implementation outcomes. The quantitative data was collected from the Program Evaluation Survey, which assessed program implementation, parental perceived competence, and self-efficacy. Independent t-tests were conducted to compare survey statistics between groups. The qualitative data was collected from five focus groups and analyzed using thematic analysis. The integration strategies included matching survey questions to focus group prompts and merging the qualitative and quantitative findings through a statistics-by-theme joint display. The mixed-methods findings yield a more nuanced interpretation of the quantitative survey outcomes with qualitative themes that determined implementation outcomes. The mixed-methods results reveal the telehealth intervention was acceptable, appropriate, and feasible for Chinese parents. Group-based coaching via videoconferencing could be a promising home-based service model to increase parental perceived competence. The third study aimed to explore the effectiveness of this culturally adapted telehealth intervention on both telehealth conditions. Linear Mixed Models were conducted to estimate treatment effects across time and model the longitudinal trajectories of outcomes in both children and parents. The results indicate this culturally adapted telehealth intervention effectively improved children's communication skills and social engagement and alleviated parenting stress. Specifically, group-based parent coaching via videoconferencing showed greater improvement in children's quality of life and parent's anxiety outcome. This dissertation highlights the cultural adaptation and intervention implementation, and it may serve as a reference for clinicians to develop culturally appropriate interventions. The preliminary findings in feasibility, implementation, and effectiveness indicate this culturally adapted telehealth intervention has great potential in Chinese communities. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]