Abstract: Tight oil is one of the primary targets of “exploring oil inside source kitchen” in China. Geology-engineering integration is the only way to achieve large-scale benefit development of tight oil in China. The tight oil discussed in this paper - oil in shale formations - refers to unconventional continental oil resources that can be economically developed on a large scale using existing technologies such as horizontal well volume fracturing. There are 2 aspects to the concept of “exploring oil inside source kitchen” of tight oil: identifying “sweet spot areas”, and producing from “sweet spot bodies”. According to differences in lithology of the reservoir and source-reservoir assemblages in shale formations, onshore tight oil in China can be divided into 3 main types: clastic rocks; diamictite-sedimentary tuff, and carbonate rocks. Geology-engineering integration for tight oil is a systematic industrial process, based on evaluation and identification of “sweet spot areas (intervals)”, with high and stable production from “sweet spot bodies” as the goal, and “design by reverse thinking and operation by forward construction” as the operating methodology. The focus is on the effective organization, management and integration of geological design and engineering operations, the effective evaluation and description of “sweet spot areas (intervals)”, stimulation and development of “artificial reservoirs”, and, finally, transforming blueprint designs into engineering operations and benefit production. The examples in this paper include clastic rocks of Fuyu reservoir in the Songliao Basin, Zhahaquan clastic rocks in the southwest Qaidam Basin, diamictite of Lucaogou Formation in the Jimsar Sag, sedimentary tuff of Tiaohu Formation in the Malang Sag, carbonate rocks of Lower Ganchaigou Formation in the Yingxi area of the southwest Qaidam Basin, and shales in the Da’anzhai member in central-northern Sichuan basin. This paper expounds the research progress of tight oil geology-engineering integration in PetroChina’s study and exploration areas. Three aspects of this work are described: geological evaluation and prediction; key engineering technologies, and major management measures. In the first three years of the “13th Five-Year plan”, newly-added three-level reserves were 9.97×108 t, and newly-established productivity was 225×104 t, achieving a “double harvest” of the oil and gas discovery and the construction of productivity. Finally, some preliminary suggestions for the future are proposed, which include: relying on the development of tight oil geology-engineering integration; strengthening multi-layer stereoscopic development of “artificial reservoirs”; establishing a “reference template” for different oil types in small blocks, and paying close attention to source rock oil and gas in shale formations.